02605nas a2200229 4500008004100000022001400041245015900055210006900214260000800283300001400291490000700305520174400312100002402056700003002080700001902110700002602129700002302155700002402178700002502202700001702227856013102244 2019 eng d a0897-475600aRemarkably distinct mechanical flexibility in three structurally similar semiconducting organic crystals studied by nanoindentation and molecular dynamics0 aRemarkably distinct mechanical flexibility in three structurally cFEB a1391-14020 v313 a

Distinct macroscopic mechanical responses of the three crystals of naphthalene diimide derivatives, 1Me, 1Et, and 1nPr, studied here are very intriguing because their molecular structures are very similar, with the difference only in the alkyl chain length. Among the three crystals examined, 1Me shows highly plastic bending nature, 1Et shows elastic flexibility, and 1nPr is brittle. A detailed investigation by nanoindentation and molecular dynamics (MD) simulations allowed us to correlate their distinct mechanical responses with the way the weak interactions pack in crystal structures. The elastic modulus (E) of 1Me is nearly an order of magnitude lower than that of 1Et, whereas hardness (H) is less than half. The low values of E and H of 1Me indicate that these crystals are highly compliant and offer a low resistance to plastic flow. As the knowledge of hardness and elastic modulus of molecular crystals alone is insufficient to capture their macroscopic mechanical deformation nature, that is, elastic, brittle, or plastic, we have employed three-point bending tests using the nanoindentation technique. This allowed a quantitative evaluation of flexibility of the three mechanically distinct semiconducting molecular crystals, which is important for designing larger-scale applications; these were complemented with detailed MD simulations. The elastic 1Et crystals showed remarkable flexibility even after 1000 cycles. The results emphasize that the alkyl side chains in functional organic crystals may be exploited for tuning their self-assembly as well as their mechanical properties. Hence, the study has broad implications, for example, in crystal engineering of various flexible, ordered molecular materials.

1 aDevarapalli, Ramesh1 aKadambi, Sourabh, Bhagwan1 aChen, Chun-Teh1 aKrishna, Gamidi, Rama1 aKammari, Bal, Raju1 aBuehler, Markus, J.1 aRamamurty, Upadrasta1 aReddy, Malla uhttp://library.ncl.res.in/content/remarkably-distinct-mechanical-flexibility-three-structurally-similar-semiconducting-organic01403nas a2200241 4500008004100000022001400041245008500055210006900140260000800209300001600217490000600233520059500239653003300834653001500867653002200882653003500904653001800939653002600957100002600983700002301009700002601032856010301058 2020 eng d a2365-654900aGreen catalyst Fe(OTs)(3)/SiO2 for the synthesis of 4-Pyrrolo-12-oxoquinazolines0 aGreen catalyst FeOTs3SiO2 for the synthesis of 4Pyrrolo12oxoquin cDEC a14721-147280 v53 a

An efficient and eco-friendly diversity-oriented synthetic protocol has been presented to synthesize structurally versatile drug-like molecules under solvent-free grinding in the presence of Fe(OTs)(3)/SiO2 as a catalyst. The use of Fe(OTs)(3)/SiO2 as a recyclable and reusable catalyst has been explored in the synthetic domino protocol involving one-pot, three component reaction for the synthesis of 4-pyrrolo-12-oxoquinazolines with special features of the protocol like high atom-economy, operational simplicity, short reaction time and high selectivity with excellent yields.

10a4-Pyrrolo-12-oxoquinazolines10aFe(OTs)(3)10aGreen methodology10aLiquid Assisted Grinding (LAG)10aSiO2 catalyst10aSolvent-free grinding1 aAllaka, Bhargava, Sai1 aBasavoju, Srinivas1 aKrishna, Gamidi, Rama uhttp://library.ncl.res.in/content/green-catalyst-feots3sio2-synthesis-4-pyrrolo-12-oxoquinazolines01460nas a2200241 4500008004100000022001400041245014600055210006900201260000800270300001400278490000800292520058100300653001600881653002800897653001800925653001800943653002500961100002500986700002801011700002701039700002601066856012601092 2020 eng d a1615-415000aPd-catalyzed annulation of beta-iodovinyl sulfones with 2-halophenols: a general route for the synthesis of 3-sulfonyl benzofuran derivatives0 aPdcatalyzed annulation of betaiodovinyl sulfones with 2halopheno cMAR a1317-13220 v3623 a

The palladium-catalyzed annulation between beta-iodovinyl sulfones and 2-halophenols or 1-bromo-2-naphthol or 2-bromo-3-pyridinol is presented. The annulation process involving oxa-Michael addition-elimination and intramolecular Heck reaction leading to form 2,3-disubstituted benzofurans (aryl benzofuryl sulfones) in good to high yields. The regioselective tandem construction of C-O and C-C bonds has been achieved with a variety of substitution patterns. Moreover, the tandem process is reliable at gram-scale reactions and a plausible mechanism is also proposed.

10aBenzofurans10abeta-Iodovinyl sulfones10aHeck reaction10aNaphthofurans10aoxa-Michael addition1 aReddy, Raju, Jannapu1 aKumar, Jangam, Jagadesh1 aKumari, Arram, Haritha1 aKrishna, Gamidi, Rama uhttp://library.ncl.res.in/content/pd-catalyzed-annulation-beta-iodovinyl-sulfones-2-halophenols-general-route-synthesis-301142nas a2200169 4500008004100000022001400041245017500055210006900230260000900299300001400308490000700322520045100329100002500780700001500805700002600820856012600846 2020 eng d a1477-052000aPhenylboronic acid-catalyzed tandem construction of S-S and C-S bonds: a new method for the synthesis of benzyl disulfanylsulfone derivatives from S-benzyl thiosulfonates0 aPhenylboronic acidcatalyzed tandem construction of SS and CS bon cMAY  a3243-32480 v183 a

A unique phenylboronic acid-catalyzed dimerization-sulfonylation of S-benzyl thiosulfonates has been disclosed. A metal-free tandem construction of S-S and C-S bonds is an operationally simple method to access a wide range of benzyl disulfanylsulfone derivatives in high to excellent yields. Moreover, the robustness of this tandem transformation has been demonstrated by gram-scale reactions, and a plausible mechanism is also proposed.

1 aReddy, Raju, Jannapu1 aWaheed, Md1 aKrishna, Gamidi, Rama uhttp://library.ncl.res.in/content/phenylboronic-acid-catalyzed-tandem-construction-s-s-and-c-s-bonds-new-method-synthesis01326nas a2200229 4500008004100000022001400041245013000055210006900185260000900254300001100263490000700274520050900281653002700790653001800817653002000835653002100855100002200876700002100898700002600919700002100945856013000966 2020 eng d a0040-403900aTotal synthesis and absolute configuration determination of Ktedonoketone, a benzenoid metabolite from Thermophilic bacterium0 aTotal synthesis and absolute configuration determination of Kted cNOV  a1525260 v613 a

The successful total synthesis of both enantiomers of ktedonoketone allowed us to decipher an unambiguous assignment of absolute configuration of the natural product. The concise synthesis highlights Wacker oxidation and aldol condensation as key steps. In addition to this, the current synthetic route is suitable to access a library of compounds on the similar skeleton as one can use readily available amino acids and Grignard reagents as variants. (C) 2020 Elsevier Ltd. All rights reserved.

10aAbsolute configuration10aKtedonoketone10aTotal synthesis10aWacker oxidation1 aDandawate, Monica1 aChoudhury, Rahul1 aKrishna, Gamidi, Rama1 aReddy, Srinivasa uhttp://library.ncl.res.in/content/total-synthesis-and-absolute-configuration-determination-ktedonoketone-benzenoid-metabolite01951nas a2200217 4500008004100000022001400041245018200055210006900237260000900306520106300315653002101378653004201399653001901441653002201460653002301482100002701505700002801532700002601560700002501586856012201611 2021 eng d a0039-788100aNickel-catalyzed difunctionalization of alkynyl bromides with thiosulfonates and N-arylthio succinimides: a convenient synthesis of 1,2-thiosulfonylethenes and 1,1-dithioethenes0 aNickelcatalyzed difunctionalization of alkynyl bromides with thi cAPR 3 a

An efficient nickel-catalyzed vicinal thiosulfonylation of 1bromoalkynes with thiosulfonates in the presence of cesium carbonate is described. An operationally simple and highly regioselective atom transfer radical addition (ATRA) of alkynyl bromides provides a wide range of (E)-1,2-thiosulfonylethenes (alpha-aryl-beta-thioarylvinyl sulfones) in moderate to high yields. The extensive substrate scope of both alkynyl bromides and thiosulfonates is explored with a broad range of functional groups. Indole-derived 1,1- bromoalkenes were also successfully explored in this 1,2-thiosulfonylation process. Moreover, the nickel-catalyzed geminal- dithiolation of alkynyl bromides with N-arylthio succinimides provides 1,1-dithioalkenes in high yields. The present protocol is reliable on gram scale, and a sequential one-pot bromination and thiosulfonylation of phenylacetylene is achieved in a scale-up synthesis. Following control experiments, a plausible mechanism is proposed to rationalize the experimental outcome and the vicinal thiosulfonylation.

10aalkynyl bromides10aatom transfer radical addition (ATRA)10athiosulfonates10athiosulfonylation10avinyl thiosulfones1 aKumari, Arram, Haritha1 aKumar, Jangam, Jagadesh1 aKrishna, Gamidi, Rama1 aReddy, Raju, Jannapu uhttp://library.ncl.res.in/content/nickel-catalyzed-difunctionalization-alkynyl-bromides-thiosulfonates-and-n-arylthio01326nas a2200169 4500008004100000022001400041245007100055210006500126260000900191300001600200490000700216520076900223100002200992700002601014700002201040856009401062 2021 eng d a0022-326300aStereoselective total synthesis of (+/-)-pleurospiroketals A and B0 aStereoselective total synthesis of pleurospiroketals A and B cOCT  a13572-135820 v863 aA full account of our efforts toward the stereoselective total synthesis of sesquiterpenoid-derived natural products (+/-)-pleurospiroketals A and B is described. Commercially available 3-methyl-2-cyclohexenone and 2,2-dimethyloxirane were used as key building blocks, and the substrate-controlled stereoselection was exploited to access the entire stereochemistry of these natural products. Initially, a planned synthetic route involving a [6,5]-bicyclic lactone intermediate was found to be insurmountable, and the later strategy comprising OsO4-NMO-mediated dihydroxylation of 3-methyl-2-cyclohexenone, followed by Luche reduction, Eschenmoser methylenation, and Bronsted acid-induced spiroketalization steps, was ultimately identified as the reliable strategy.1 aThorat, Sagar, S.1 aKrishna, Gamidi, Rama1 aKontham, Ravindar uhttp://library.ncl.res.in/content/stereoselective-total-synthesis-pleurospiroketals-and-b01114nas a2200181 4500008004100000022001400041245015600055210006900211260000900280300001400289490000700303520040700310100002500717700002100742700002600763700002100789856012200810 2021 eng d a1523-706000aTuning of alpha-silyl carbocation reactivity into enone transposition: application to the synthesis of peribysin D, E-volkendousin, and E-guggulsterone0 aTuning of alphasilyl carbocation reactivity into enone transposi cSEP  a6642-66470 v233 aA reliable method for enone transposition has been developed with the help of silyl group masking. Enantio-switching, substituent shuffling, and Z-selectivity are the highlights of the method. The developed method was applied for the first total synthesis of peribysin D along with its structural revision. Formal synthesis of E-guggulsterone and E-volkendousin was also claimed using a short sequence.1 aAthawale, Paresh, R.1 aZade, Vishal, M.1 aKrishna, Gamidi, Rama1 aReddy, Srinivasa uhttp://library.ncl.res.in/content/tuning-alpha-silyl-carbocation-reactivity-enone-transposition-application-synthesis01630nas a2200193 4500008004100000022001400041245015300055210006900208260000900277300001400286490000700300520087800307100002501185700002101210700002801231700002301259700002601282856012801308 2022 eng d a1144-054600aDiethyl phosphite-mediated switchable synthesis of bis(imidazoheterocycles) derived disulfanes and sulfanes using imidazoheterocycles and octasulfur0 aDiethyl phosphitemediated switchable synthesis of bisimidazohete cMAR  a4784-47910 v463 a

A practical and highly efficient oxidative dual C-H sulfenylation of imidazoheterocycles using odorless, inexpensive elemental sulfur in DMSO to synthesize sulfur-bridged imidazoheterocycles under metal-free conditions is reported. The amount of diethyl phosphite and sulfur powder most attractively permits a tunable synthesis of bis(imidazoheterocycle)disulfanes and bis(imidazoheterocycle)sulfanes in good to high yields. A comprehensive substrate scope with a broad range of functional group tolerance was realized, and the efficacy of the process was proved at gram-scale reactions. Next, the bis(imidazopyridine)disulfanes were smoothly reacted with various indoles under similar conditions to form the corresponding imidazo[1,2-a]pyridine-indole-derived thioethers in high yields. A plausible mechanism has been proposed based on the control experiments.

1 aReddy, Raju, Jannapu1 aShankar, Angothu1 aKumar, Jangam, Jagadesh1 aSharadha, Nunavath1 aKrishna, Gamidi, Rama uhttp://library.ncl.res.in/content/diethyl-phosphite-mediated-switchable-synthesis-bisimidazoheterocycles-derived-disulfanes01584nas a2200241 4500008004100000022001400041245017600055210006900231260000800300300001200308490000800320520067300328653003201001653002001033653003101053653001501084653001901099100002501118700001501143700002701158700002601185856013101211 2022 eng d a1615-415000aInterrupted CuAAC-thiolation for the construction of 1,2,3-triazole-fused eight-membered heterocycles from O-/N-propargyl derived benzyl thiosulfonates with organic azides0 aInterrupted CuAACthiolation for the construction of 123triazolef cJAN a319-3250 v3643 aA copper(I)-catalyzed interrupted click-sulfenylation of O-/N-propargyl benzyl thiosulfonates with organic azides has been disclosed. The unified CuAAC-thiolation provides a wide range of triazole-fused eight-membered heterocycles in good to high (51-94%) yields under mild reaction conditions. Moreover, a three-component reaction is also achieved involving O-/N-propargyl benzyl thiosulfonates, benzyl bromide, and sodium azide to deliver fused-triazoles in 61-74% yields. From a synthetic point of view, the present protocol has been demonstrated at gram-scale reactions. A plausible mechanism is also proposed based on experimental results and control experiments.10aEight-Membered Heterocycles10aFused-Triazoles10aInterrupted-Click Reaction10aThiolation10athiosulfonates1 aReddy, Raju, Jannapu1 aWaheed, Md1 aKumari, Arram, Haritha1 aKrishna, Gamidi, Rama uhttp://library.ncl.res.in/content/interrupted-cuaac-thiolation-construction-123-triazole-fused-eight-membered-heterocycles-o-n01866nas a2200229 4500008004100000022001400041245017400055210006900229260000900298300001400307490000800321520099000329653003201319653001601351653002001367653002801387653001301415100002501428700002801453700002601481856012901507 2022 eng d a1615-415000aK3PO4-promoted cycloannulation of (E)-beta-Iodovinyl Sulfones with ortho-Hydroxy-chalcones/cinnamates for the synthesis of 2,3,4-trisubstituted 4h-benzopyran derivatives0 aK3PO4promoted cycloannulation of EbetaIodovinyl Sulfones with or cDEC  a4080-40870 v3643 a

K3PO4-mediated cycloannulation of (E)-beta-iodovinyl sulfones with ortho-hydroxy chalcones/ortho-hydroxy cinnamates has been realized to access 2,3,4-trisubstituted-4H-benzopyran derivatives. A metal-free tandem oxa-Michael addition and cycloannulation allows the diversity-oriented synthesis of the corresponding 3-sulfonyl-4H-benzopyrans in good to high yields. More importantly, one-pot three-component reaction between (E)-beta-iodovinyl sulfones, 2-hydroxybenzaldehydes, and phosphonium ylides has been established for the synthesis of 4H-chromene derivatives in moderate to good yields. Notably, this metal-free process features a broad substrate scope and easy elaboration into numerous multifaceted chromene products, including bioactive estrone-derivative. The present protocol is sustainable at the gram scale reactions, and post-synthetic applications were also demonstrated. A plausible mechanism is also presented on the basis of existing experimental results.

10a(E)-beta-Iodovinyl sulfones10aBenzopyrans10aCycloannulation10aortho-Hydroxy Chalcones10aSulfones1 aReddy, Raju, Jannapu1 aKumar, Jangam, Jagadesh1 aKrishna, Gamidi, Rama uhttp://library.ncl.res.in/content/k3po4-promoted-cycloannulation-e-beta-iodovinyl-sulfones-ortho-hydroxy-chalconescinnamates02136nas a2200217 4500008004100000245016400041210006900205260000800274300001400282490000700296520127000303100003101573700002301604700002601627700002601653700002101679700002501700700003301725700003001758856013001788 2022 eng d00aNovel pharmaceutical cocrystal of apalutamide, a nonsteroidal antiandrogen drug: synthesis, crystal structure, dissolution, stress, and excipient compatibility0 aNovel pharmaceutical cocrystal of apalutamide a nonsteroidal ant cJAN a1130-11420 v223 aApalutamide (APA), a second-generation nonsteroidal antiandrogen BCS Class II drug with poor solubility and high permeability. A novel 1:1 cocrystal of Apalutamide (APA) with methylparaben (MP) was identified by cooling crystallization during the cocrystal screening and characterized by various solid-state techniques, such as PXRD, DSC, TGA, FT-IR, and 13C solid-state CP-MAS NMR spectroscopy. The crystal structures of APA and its cocrystal (APA-MP) were determined by the SC-XRD technique. The crystal structure analysis of the APA-MP cocrystal revealed that the APA and MP molecules are connected through strong O–H···O hydrogen bonds. The novel cocrystal improves the solubility and dissolution rate in different physiological conditions compared to poorly soluble APA due to strong hydrogen bond between the drug and the coformer. The cocrystal is stable (physically and chemically) under stress conditions, such as exposure to the relative humidity, mechanical grinding, open exposure to atmosphere at cRT (critical room temperature) and compression pressure of 10 tons. In addition, the compatibility of the cocrystal with excipients used in the drug product of APA (ERLEADA) was also investigated, and no disproportionation of cocrystal was observed.1 aSaladi, Venkata, Narasayya1 aKammari, Bal, Raju1 aMandad, Pratap, Reddy1 aKrishna, Gamidi, Rama1 aSajja, Eswaraiah1 aThirumali, Rajan, S.1 aMarutapilli, Arthanareeswari1 aMathad, Vijayavitthal, T. uhttp://library.ncl.res.in/content/novel-pharmaceutical-cocrystal-apalutamide-nonsteroidal-antiandrogen-drug-synthesis-crystal01461nas a2200205 4500008004100000022001400041245010200055210006900157260000800226300001400234490000700248520074800255100001701003700002201020700001601042700002601058700002201084700002101106856012801127 2022 eng d a0022-326300aReady access to benzannulated [5,5]-oxaspirolactones using Au(III)-catalyzed cascade cyclizations0 aReady access to benzannulated 55oxaspirolactones using AuIIIcata cMAR a3025-30410 v873 a

This work showcases an unprecedented Au(III)-catalyzed cascade cyclization of 2-(4-hydroxyalkynyl)benzoates to access benzannulated [5,5]-oxaspirolactones related to biologically active natural products. This reaction proceeds through an initial 5-endo-dig mode of hydroalkoxylation of the alkynol segment to give the oxocarbenium species (via cyclic enol-ether) followed by the addition of carboxylate onto the oxocarbenium that delivers the oxaspirolactone scaffold. While testing this method's scope, we found that the steric and electronic environment of the hydroxyl group could alter the reaction pathway that delivers isochromenone through a competitive 6-endo-dig mode of attack of the carboxylate onto the tethered alkyne.

1 aMankad, Yash1 aThorat, Sagar, S.1 aDas, Pronay1 aKrishna, Gamidi, Rama1 aKontham, Ravindar1 aReddy, Srinivasa uhttp://library.ncl.res.in/content/ready-access-benzannulated-55-oxaspirolactones-using-auiii-catalyzed-cascade-cyclizations02044nas a2200181 4500008004100000022001400041245016200055210006900217260000800286300001400294490000700308520132400315100002501639700002701664700002301691700002601714856012201740 2022 eng d a0022-326300aSolvent-driven mono- and bis-sulfenylation of (E)-beta-iodovinyl sulfones with thiols for flexible synthesis of 1,2-thiosulfonylalkenes and 1,2-dithioalkenes0 aSolventdriven mono and bissulfenylation of Ebetaiodovinyl sulfon cMAR a3934-39510 v873 a

The nature of solvent is a key factor for stereoselective mono-and bis-thiolation of (E)-beta-iodovinyl sulfones with thiols under basic conditions. A novel and unprecedented vicinal bisthiolation of (E)-beta-iodovinyl sulfones with thiols under the influence of K2CO3/DMSO at room temperature for quick assembly of (E)-1,2-dithio-1-alkenes is presented. Solvent-induced stereoselective monosulfenylation of (E)-beta-iodovinyl sulfones with thiols has also been established for the synthesis of both (E)- and (Z)-1,2-thiosulfonylethenes in MeCN and MeOH, respectively. Moreover, K2CO3-mediated desulfonylative-sulfenylation of (Z)-1,2-thiosulfonylethenes with thiols in DMSO furnished unsymmetrical (Z)-1,2-dithio-1-alkenes for the first time. The solvent-dependent versatile reactivity of (E)-beta-iodovinyl sulfones has been successfully explored to provide a set of (E)-/(Z)-1,2-dithio-1-alkenes and (E)-/(Z)-1,2-thiosulfonyl-1-alkenes in good to high yields with excellent stereoselectivities. Notably, this operationally simple process utilizes a broad substrate scope with good functional group tolerance and compatibility. The efficacy of the process has been proven for gram-scale reactions, and plausible mechanistic models are outlined on the basis of experimental results and control experiments.

1 aReddy, Raju, Jannapu1 aKumari, Arram, Haritha1 aSharadha, Nunavath1 aKrishna, Gamidi, Rama uhttp://library.ncl.res.in/content/solvent-driven-mono-and-bis-sulfenylation-e-beta-iodovinyl-sulfones-thiols-flexible01514nas a2200253 4500008004100000022001400041245006700055210006400122260000800186300001500194490000900209520070300218653001600921653003500937653002100972653002900993653002001022100002101042700002701063700002601090700002601116700002101142856009701163 2022 eng d a1434-193X00aTotal synthesis of 12, 13-dibenzyl-banistenoside B and analogs0 aTotal synthesis of 12 13dibenzylbanistenoside B and analogs cMAY ae2022002220 v20223 a

Banistenosides A and B possessing a unique ``azepino(1,2-a)tetrahydro-beta-carboline'' carbon framework were isolated from the stem of Banisteriopsis caapi and showed MAO-A inhibition. Herein, we report the total synthesis of dibenzyl derivative of the untouched natural product in the last two decades, Banistenoside B. The key steps involve construction of 6.5.6.7 tetracyclic core using Pictet-Spengler reaction and intramolecular amide coupling. The stereoselective glycation was achieved through Hotha's protocol using gold catalyst, and silver triflate in the late stage of synthesis. The stereochemistry of most of the essential compounds were confirmed by X-ray crystallography.

10aAu-catalyst10aMultiple steps total synthesis10aNatural products10aPictet-Spengler reaction10aWittig reaction1 aPatil, Suhag, S.1 aJachak, Gorakhnath, R.1 aKrishna, Gamidi, Rama1 aArgade, Narshinha, P.1 aReddy, Srinivasa uhttp://library.ncl.res.in/content/total-synthesis-12-13-dibenzyl-banistenoside-b-and-analogs01574nas a2200193 4500008004100000022001400041245016200055210006900217260000900286300001600295490000700311520081500318100002201133700001901155700002401174700002601198700002801224856012801252 2023 eng d a0022-326300aCarbamate-Protected (BOC and O-NB) 2-Aminopyrimidinedione-based janus G-C nucleobase motifs as building blocks for supramolecular assembly and smart polymers0 aCarbamateProtected BOC and ONB 2Aminopyrimidinedionebased janus  cOCT  a14953-149590 v883 a

In this paper, we report ``carbamate protected'' 2-aminopyrimidinedione-based Janus G-C nucleobases (2-APD Janus G-C nucleobases) featuring polymerizable groups and self-complementary triple H-bonding motifs DDA and AAD as building blocks for developing smart polymers and self-healing materials. The carbamate-masked H-bonding motif, cleavable under acidic (BOC group) or photocleavable (O-nitrobenzyl group) conditions, would facilitate the synthesis of smart polymers by alleviating aggregation during polymerization which in turn would exclude self-assembly-assisted solubility issues. Ready accessibility in excellent yields coupled with the possibility for facile introduction of polymerizable groups would make these building blocks excellent candidates for diverse polymerization applications.

1 aSingh, Dharmendra1 aLakshmi, Durga1 aMeena, Chhuttan, L.1 aKrishna, Gamidi, Rama1 aSanjayan, Gangadhar, J. uhttp://library.ncl.res.in/content/carbamate-protected-boc-and-o-nb-2-aminopyrimidinedione-based-janus-g-c-nucleobase-motifs01824nas a2200229 4500008004100000245010500041210006900146260000800215300000900223490000700232520104100239653002001280653002001300653001501320653003001335653001801365100002301383700002601406700001901432700001601451856012701467 2023 eng d00aOrigin of optoelectronic contradictions in 3,4-cycloalkyl[c]-chalcogenophenes: a computational study0 aOrigin of optoelectronic contradictions in 34cycloalkylcchalcoge cNOV a42400 v153 a

The planar morphology of the backbone significantly contributes to the subtle optoelectronic features of pi-conjugated polymers. On the other hand, the atomistic tuning of an otherwise identical pi-backbone could also impact optoelectronic properties systematically. In this manuscript, we compare a series of 3,4-cycloalkylchalcogenophenes by tuning them atomistically using group-16 elements. Additionally, the effect of systematically extending these building blocks in the form of oligomers and polymers is studied. The size of the 3,4-substitution affected the morphology of the oligomers. In addition, the heteroatoms contributed to a further alteration in their geometry and resultant optoelectronic properties. The chalcogenophenes, containing smaller 3,4-cycloalkanes, resulted in lower bandgap oligomers or polymers compared to those with larger 3,4-cycloalkanes. Natural bonding orbital (NBO) calculations were performed to understand the disparity alongside the contour maps of frontier molecular orbitals (FMO).

10achalcogenophene10aDFT calculation10aMorphology10aoptoelectronic properties10asteric effect1 aMasilamani, Ganesh1 aKrishna, Gamidi, Rama1 aDebnath, Sashi1 aBedi, Anjan uhttp://library.ncl.res.in/content/origin-optoelectronic-contradictions-34-cycloalkylc-chalcogenophenes-computational-study01719nas a2200169 4500008004100000022001400041245019400055210006900249260000900318300001400327490000700341520099300348100002501341700002301366700002601389856013401415 2023 eng d a0022-326300aPd(II)-catalyzed tandem cycloannulative-alkenylation of o-alkynyl-phenols/anilines with (E)-β-Iodovinyl sulfones: a direct strategy to construct 3-(Vinyl sulfonyl)benzoheterole derivatives0 aPdIIcatalyzed tandem cycloannulativealkenylation of oalkynylphen cJUN  a8889-89030 v883 a

Benzoheterolesand vinyl sulfones are the most promisingpharmaceuticalrelevance motifs, yet the hybrid analogues of these scaffolds stillneed to be explored. We report herein a general and highly efficientPd(OAc)(2)-catalyzed intramolecular cyclization and vinylationof o-alkynylphenols/o-alkynylanilineswith (E)-beta-iodovinyl sulfones under mild reactionconditions. A direct C(sp(2))-C(sp(2)) cross-couplingis enabled for the diversity-oriented synthesis of vinyl sulfone-tetheredbenzofurans and indoles in good to high yields with excellent stereoselectivity.Notably, this tandem process was consistent at the gram scale, andin situ, generation of 2-(phenylethynyl)phenol has also been utilizedin a scalable synthesis. Late-stage synthetic transformations werealso further explored, including isomerization and desulfonylative-sulfenylation.Moreover, several control experiments were accomplished, and we proposeda plausible mechanism based on existing experimental results.

1 aReddy, Raju, Jannapu1 aSharadha, Nunavath1 aKrishna, Gamidi, Rama uhttp://library.ncl.res.in/content/pdii-catalyzed-tandem-cycloannulative-alkenylation-o-alkynyl-phenolsanilines-e-%CE%B2-iodovinyl01307nas a2200193 4500008004100000022001400041245018800055210006900243260000800312300001400320490000700334520055400341100001700895700001700912700001800929700002600947700001500973856012500988 2023 eng d a0022-326300aRadical cascade cyclization of unactivated alkene-tethered indoles with aryldiazonium salt and sodium metabisulfite to access Azo- and Sulfonylated-2,3-Dihyro-1H-pyrrolo[1,2-a]indoles0 aRadical cascade cyclization of unactivated alkenetethered indole cJUN a9123-91290 v883 a

A method for the construction ofheterocyclic scaffold2,3-dihyro-1H-pyrrolo[1,2-a]indolesvia arylsulfonylradical-triggered cascade cyclization of unactivated alkene-tetheredindoles in the absence of any external photocatalyst has been developed.This protocol features easily accessible starting materials such assodium metabisulfite and aryldiazonium tetrafluoroborates at roomtemperature and offers good functional group compatibility, enablingthe introduction of various functionalized sulfonyl and azo groupsinto pyrrolo[1,2-a]indoles.

1 aKumar, Pawan1 aRai, Archana1 aKumar, Manish1 aKrishna, Gamidi, Rama1 aDas, Utpal uhttp://library.ncl.res.in/content/radical-cascade-cyclization-unactivated-alkene-tethered-indoles-aryldiazonium-salt-and01590nas a2200229 4500008004100000022001400041245014200055210006900197260000800266300001600274490000700290520076700297653001701064653001601081653001501097100002201112700002201134700002501156700002601181700002201207856013101229 2023 eng d a0022-326300aRegioselective synthesis of benzannulated [5,6]-oxaspirolactones via Cu(II)-catalyzed cycloisomerization of 2-(5-Hydroxyalkynyl)benzoates0 aRegioselective synthesis of benzannulated 56oxaspirolactones via cNOV a16915-169330 v883 a

Spiroketals and oxaspirolactones are widely found in biologically active natural products, serving as important structural motifs. In this study, we present a Cu-(II)-catalyzed cascade cycloisomerization of 2-(5-hydroxyalkynyl)-benzoates, enabling the regioselective synthesis of benzannulated [5,6]-oxaspirolactones containing an isochromen-1-one moiety. This strategy offers a rapid and efficient approach to access a diverse array of benzannulated [5,6]-oxaspirolactones. The methodology presented here showcases a broad substrate scope, delivering good yields and scalability up to gram scale. The structures of the oxaspirolactones were unequivocally confirmed through single-crystal X-ray analysis and by analogy using H-1 and C-13-{H-1} NMR data.

10aConstruction10aIsocumarins10aStrategies1 aThorat, Sagar, S.1 aShimpi, Sagar, P.1 aSambherao, Pooja, I.1 aKrishna, Gamidi, Rama1 aKontham, Ravindar uhttp://library.ncl.res.in/content/regioselective-synthesis-benzannulated-56-oxaspirolactones-cuii-catalyzed-cycloisomerization01139nas a2200193 4500008004100000022001400041245015400055210006900209260000800278300001400286490000700300520040300307100002400710700001800734700002300752700002600775700001500801856012900816 2023 eng d a2052-412900aSynthesis of N-functionalized 2,3-disubstituted benzofurans/naphthofurans from para-quinone methides and isocyanides via the [4+1] annulation pathway0 aSynthesis of Nfunctionalized 23disubstituted benzofuransnaphthof cJUL a3746-37510 v103 a

A scandium triflate catalyzed [4 + 1] cycloaddition reaction of 2-hydroxy-substituted para-quinone methides and isocyanides has been developed. This operationally simple, efficient and practical protocol provides straightforward access to a variety of N-functionalized 2,3-disubstituted benzofuran/naphthofuran derivatives with broad functional group compatibility and good scalability.

1 aKale, Someshwar, B.1 aKumar, Manish1 aShinde, Dinesh, R.1 aKrishna, Gamidi, Rama1 aDas, Utpal uhttp://library.ncl.res.in/content/synthesis-n-functionalized-23-disubstituted-benzofuransnaphthofurans-para-quinone-methides01210nas a2200181 4500008004100000022001400041245019700055210006900252260000800321300001400329490000700343520045700350100002200807700002100829700002600850700002100876856013100897 2023 eng d a0163-386400aTotal synthesis and absolute configuration determination of the α-glycosidase inhibitor (3S,4R)-6-Acetyl-3-hydroxy-2,2-dimethylchroman-4-yl (Z)-2-Methylbut-2-enoate from Ageratina grandifolia0 aTotal synthesis and absolute configuration determination of the  cJUN a1878-18830 v863 a

Herein, we report the first total synthesis of & alpha;-glycosidaseinhibitor (3R, 4S)-6-acetyl-3-hydroxy-2,2-dimethylchroman-4-yl(Z)-2-methylbut-2-enoate as well as its enantiomer.Our synthesis confirms the chromane structure separately proposedby Navarro-Vazquez and Mata, on the basis of DFT computations. Furthermore,our synthesis allowed us to determine the absolute configuration ofthe natural compound as (3S, 4R)and not (3R, 4S).

1 aDandawate, Monica1 aChoudhury, Rahul1 aKrishna, Gamidi, Rama1 aReddy, Srinivasa uhttp://library.ncl.res.in/content/total-synthesis-and-absolute-configuration-determination-%CE%B1-glycosidase-inhibitor-3s4r-600658nas a2200157 4500008004100000022001400041245013300055210006900188260000800257300001100265100002100276700002600297700002600323700002300349856012800372 2023 eng d a1551-700400aUltrasound assisted synthesis of spirooxindolo-1,2,4-oxadiazoles via [3+2] cycloaddition reaction and their anti-cancer activity0 aUltrasound assisted synthesis of spirooxindolo124oxadiazoles via cMAY aS1-S461 aKanchrana, Madhu1 aAllaka, Bhargava, Sai1 aKrishna, Gamidi, Rama1 aBasavoju, Srinivas uhttp://library.ncl.res.in/content/ultrasound-assisted-synthesis-spirooxindolo-124-oxadiazoles-32-cycloaddition-reaction-and00655nas a2200145 4500008004100000022001400041245014100055210006900196300001800265100002100283700002600304700002600330700002300356856013000379 2023 eng d a1551-700400a Ultrasound assisted synthesis of spirooxindolo-1,2,4-oxadiazoles via [3+2] cycloaddition reaction and their anti-cancer activity0 aUltrasound assisted synthesis of spirooxindolo124oxadiazolesi vi aSpecial Issue1 aKanchrana, Madhu1 aAllaka, Bhargava, Sai1 aKrishna, Gamidi, Rama1 aBasavoju, Srinivas uhttp://library.ncl.res.in/content/ultrasound-assisted-synthesis-spirooxindolo-124-oxadiazoles-32-cycloaddition-reaction-and-001147nas a2200193 4500008004100000022001400041245015100055210006900206260000800275300001400283490000700297520039900304100002400703700002200727700002500749700002600774700002200800856013100822 2024 eng d a1359-734500aDivergent access to polycyclic spiro- and fused-N,O-ketals through Bi(OTf)3-catalyzed [4+2]-annulation of cyclic N-sulfonyl ketimines and alkynols0 aDivergent access to polycyclic spiro and fusedNOketals through B cJAN a1144-11470 v603 a

Bismuth(iii) triflate-catalyzed [4+2]-annulation of cyclic N-sulfonyl ketimines (derived from saccharin) and alkynyl alcohols (4-pentyn-1-ols and 5-hexyn-1-ols) has been reported. This cascade annulation provides a diverse array of polycyclic spiro-and-fused N,O-ketals with excellent substrate scope, good isolated yields, and diastereoselectivities under mild reaction conditions.

1 aNakate, Ashwini, K.1 aKataria, Priyanka1 aSambherao, Pooja, I.1 aKrishna, Gamidi, Rama1 aKontham, Ravindar uhttp://library.ncl.res.in/content/divergent-access-polycyclic-spiro-and-fused-no-ketals-through-biotf3-catalyzed-42-annulation01257nas a2200169 4500008004100000022001400041245014400055210006900199260000900268300001400277490000700291520058000298100002300878700002600901700002600927856013400953 2024 eng d a0022-326300aMetal-free one-pot domino synthesis of oxazolidinethione derivatives of quaternary amino acids from α-amino esters and aldehydes using CS20 aMetalfree onepot domino synthesis of oxazolidinethione derivativ cFEB  a7109-71140 v893 a

We present a streamlined, metal-free, one-pot domino approach to efficiently synthesize oxazolidinethione derivatives containing substituted quaternary amino acids. This method employs alpha-amino esters, aldehydes, and CS2 under mild conditions, constructing three new bonds (C-N, C-C, and C-O) to produce oxazolidinethione compounds featuring a quaternary center and a beta-hydroxy derivative in high yields. This scalable protocol enables the creation of libraries of biologically significant, intricate amino acid derivatives using amino esters and aldehydes.

1 aShinde, Dinesh, R.1 aKrishna, Gamidi, Rama1 aMarelli, Udaya, Kiran uhttp://library.ncl.res.in/content/metal-free-one-pot-domino-synthesis-oxazolidinethione-derivatives-quaternary-amino-acids-%CE%B102753nas a2200229 4500008004100000245008700041210006900128260000900197300001200206490000700218520202400225653001702249653001202266653001502278653000902293653001902302100002502321700002002346700002602366700002102392856011002413 2024 eng d00aNovel molecular adducts of an anti-cancer drug vandetanib with enhanced solubility0 aNovel molecular adducts of an anticancer drug vandetanib with en cJAN  a248-2600 v263 a

The solubility, permeability, and dissolution rate of an active pharmaceutical ingredient (API) are critical factors in determining its pharmacokinetic performance in oral dosage forms. Modifying these properties can potentially enhance the drug's pharmacokinetics. Vandetanib (VDTB), classified as a class II anti-cancer drug in the biopharmaceutical classification system (BCS), suffers from low solubility (0.008 mg mL-1) and an extended pharmacokinetic half-life (19 days), necessitating the administration of high doses, which leads to undesirable side effects. To address this issue, we have employed a crystal engineering approach to enhance the solubility of VDTB. We employed the liquid-assisted grinding (LAG) method followed by the slow evaporation technique to prepare novel solid forms of VDTB by incorporating various aliphatic dicarboxylic acids, including succinic acid (SUA), adipic acid (ADA), pimelic acid (PIA), azelaic acid (AZA), and sebacic acid (SBA). These newly obtained solid forms were characterized by SC-XRD, PXRD, TGA, and DSC experiments. The crystal structure analyses revealed a proton transfer between the carboxylic acid group of aliphatic acids and the N-methyl piperidine moiety of VDTB, confirming salt/adduct formation. Additionally, all of the molecular salts were stabilized by charge-assisted N+-HMIDLINE HORIZONTAL ELLIPSISO- hydrogen bonds, while the parent VDTB crystal structure is stabilised by N-HMIDLINE HORIZONTAL ELLIPSISN interactions. Moreover, the solubility and dissolution rate of these new solid forms were assessed in a pH 7.4 phosphate buffer medium, with the results indicating that all of the solid forms, except for VDTB:SBA, exhibited higher solubility compared to pure VDTB. These findings offer promising prospects for the development of an improved VDTB formulation with enhanced pharmacokinetic properties. Successful attempt to improve the solubility and dissolution rate of Vandetanib - an anti-cancer drug, by crystal engineering approach.

10aAmorfization10ahydrate10aParameters10aSalt10aThyroid-Cancer1 aBandaru, Ravi, Kumar1 aGiri, Lopamudra1 aKrishna, Gamidi, Rama1 aDandela, Rambabu uhttp://library.ncl.res.in/content/novel-molecular-adducts-anti-cancer-drug-vandetanib-enhanced-solubility01683nas a2200181 4500008004100000022001400041245008500055210006900140260000900209300001400218490000700232520106700239100002001306700002001326700002601346700002001372856010901392 2024 eng d a1477-922600aTransfer semi-hydrogenation of terminal alkynes with a well-defined iron complex0 aTransfer semihydrogenation of terminal alkynes with a welldefine cFEB  a3484-34890 v533 a

The synthesis and characterization of a bis-iron(ii) complex was accomplished upon treatment of a phosphine free NNN-pincer ligand (L) with FeCl2 center dot 4H2O under ambient conditions. The deep greenish colored iron(ii) complex (Fe-1) was characterized by a single-crystal X-ray diffraction study along with IR spectroscopy, UV-Vis spectroscopy, mass spectrometry, and elemental analysis. The Fe-1 complex was tested for the transfer semi-hydrogenation of terminal alkynes to the corresponding alkenes through the dehydrogenation of dimethyl amine-borane. This procedure enables the conversion of various structurally different terminal alkynes to alkenes under mild conditions. Control experiments were performed to shed light on the possible intermediates generated during the present protocol. A bench stable iron(ii) complex with the pincer ligand backbone was synthesized and characterized. The well-defined iron complex was successfully utilized for the dehydrogenation of DMAB and subsequent transfer semi-hydrogenation of terminal alkynes.

1 aChowdhury, Deep1 aGoswami, Souvik1 aKrishna, Gamidi, Rama1 aMukherjee, Arup uhttp://library.ncl.res.in/content/transfer-semi-hydrogenation-terminal-alkynes-well-defined-iron-complex