01387nas a2200241 4500008004100000022001400041245010900055210006900164260010600233300001400339490000700353520048700360653002200847653002300869653001500892653001400907653001500921100001900936700001700955700002400972700002300996856012601019 2006 eng d a0040-403900aPalladium mediated cycloisomerization of sugar alkynols: synthesis of cyclic enol-ethers and spiroketals0 aPalladium mediated cycloisomerization of sugar alkynols synthesi aTHE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLANDbPERGAMON-ELSEVIER SCIENCE LTDcMAY a3649-36520 v473 a

Functionalized bicyclic enol-ethers and spiroketals are prepared by Pd catalyzed cycloisomerization of 3-C-alkynylfuranosyl derivatives. Cycloisomerization of differently substituted alkyne derivatives revealed a preference for 6-endo-dig cyclization over 5-exo-dig if the substituent is not sufficiently electron withdrawing. The scope of these cycloisomerizations has been further extended by integrating with conjugate addition. (c) 2006 Elsevier Ltd. All rights reserved.

10ac-alkynylfuranose10acycloisomerization10aenol-ether10aPalladium10aSpiroketal1 aRamana, C., V.1 aMallik, Rosy1 aGonnade, Rajesh, G.1 aGurjar, Mukund, K. uhttp://library.ncl.res.in/content/palladium-mediated-cycloisomerization-sugar-alkynols-synthesis-cyclic-enol-ethers-and-001501nas a2200181 4500008004100000022001400041245014500055210006900200260010600269300001400375490000700389520070700396100002301103700002401126700002401150700002801174856011701202 2008 eng d a0040-403900aPre-organization-mediated macrocylization: efficient synthesis and structural investigations of BINOL-m-phenylenediamine-derived macrocycles0 aPreorganizationmediated macrocylization efficient synthesis and  aTHE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLANDbPERGAMON-ELSEVIER SCIENCE LTDcMAR a2139-21420 v493 a

This letter describes a serendipitous discovery of an efficient synthetic route to BINOL-m-phenylenediamine-derived macrocycles. These macrocycles are quickly accessible in an one-pot procedure by the direct condensation of (R) and (S) BINOL bis-acids with suitably substituted m-phenylenediamine analogs. Structural investigations by single crystal X-ray crystallography and solution-state NMR studies provided convincing evidence of their intramolecular hydrogen bonding arrangement and rigid structural architecture. The striking feature of these macrocycles is their ready accessibility in optically pure form coupled with their ease of synthesis. (C) 2008 Elsevier Ltd. All rights reserved.

1 aSrinivas, Deekonda1 aGonnade, Rajesh, G.1 aRajamohanan, P., R.1 aSanjayan, Gangadhar, J. uhttp://library.ncl.res.in/content/pre-organization-mediated-macrocylization-efficient-synthesis-and-structural-001046nas a2200169 4500008004100000022001400041245012500055210006900180260007100249300001400320490000700334520033600341100001900677700002800696700002400724856012800748 2009 eng d a0022-326300aPd(II)-mediated alkynediol spiroketalization: first total synthesis of (-)-cephalosporolide E and (+)-cephalosporolide F0 aPdIImediated alkynediol spiroketalization first total synthesis  a1155 16TH ST, NW, WASHINGTON, DC 20036 USAbAMER CHEMICAL SOCcAPR a2842-28450 v743 a

Herein we describe a concise assembly of the central 1.6-dioxaspiro[4.4]nonane core of cephalosporolides E/F by employing a Pd-mediated alkynediol cycloisomerization and their total synthesis. On the basis of spectroscopic data and optical rotation values, the absolute configurations of cephalosporolides E/F were proposed.

1 aRamana, C., V.1 aSuryawanshi, Sharad, B.1 aGonnade, Rajesh, G. uhttp://library.ncl.res.in/content/pdii-mediated-alkynediol-spiroketalization-first-total-synthesis-cephalosporolide-e-and-000955nas a2200169 4500008004100000022001400041245007300055210006800128260007100196300001600267490000700283520032800290100001900618700002000637700002400657856010400681 2013 eng d a0022-326300aProline-catalyzed asymmetric synthesis of syn- and anti-1,3-diamines0 aProlinecatalyzed asymmetric synthesis of syn and anti13diamines a1155 16TH ST, NW, WASHINGTON, DC 20036 USAbAMER CHEMICAL SOCcDEC a11756-117640 v783 a

A general organocatalytic strategy for asymmetric synthesis of both syn/anti-1,3-diamines has been developed. The strategy employs proline-catalyzed sequential alpha-amination and Horner-Wadsworth-Emmons (HWE) olefination of aldehydes as the key step where syn-1,3-diamine was obtained as the most favorable product.

1 aKumar, Pradeep1 aJha, Vishwajeet1 aGonnade, Rajesh, G. uhttp://library.ncl.res.in/content/proline-catalyzed-asymmetric-synthesis-syn-and-anti-13-diamines-001592nas a2200229 4500008004100000022001400041245014600055210006900201260007700270300001400347520068100361653002501042653002501067653002101092653001201113653002401125653002001149100002401169700002401193700002401217856012101241 2014 eng d a1434-193X00aProtecting-group-free diastereoselective total synthesis of (+/-)-6-epi-cleistenolide and chemoenzymatic synthesis of (-)-6-epi-cleistenolide0 aProtectinggroupfree diastereoselective total synthesis of 6epicl aBOSCHSTRASSE 12, D-69469 WEINHEIM, GERMANYbWILEY-V C H VERLAG GMBHcDEC a8049-80543 a

A short, efficient, practical, and protecting-group-free diastereoselective total synthesis of (+/-)-6-epi-cleistenolide (1) has been achieved in five steps in 60% overall yield. The use of a chemoenzymatic approach also gave (-)-6-epi-cleistenolide (1) (>99.9% ee). The Achmatowicz reaction, chemoselective oxidation of a hemiacetal, diastereoselective 1,3-anti reduction of alpha-hydroxy ketone, and enzymatic resolution of a 1,3-diol are the key features of this linear total synthesis. The synthetic strategy demonstrated in this paper could be extended for an asymmetric total synthesis of (-)-cleistenolide (1) and related biologically active natural products.

10aAsymmetric synthesis10adiastereoselectivity10aEnzyme catalysis10aLipases10aOxygen heterocycles10aTotal synthesis1 aMahajan, Pankaj, S.1 aGonnade, Rajesh, G.1 aMhaske, Santosh, B. uhttp://library.ncl.res.in/content/protecting-group-free-diastereoselective-total-synthesis-6-epi-cleistenolide-and-000981nas a2200169 4500008004100000022001400041245008300055210006900138260011000207300001400317490000700331520029500338100002100633700002400654700001900678856011400697 2015 eng d a1477-052000aPd-catalyzed benzylic C-H oxidation of cyclotriveratrylene - product diversity0 aPdcatalyzed benzylic CH oxidation of cyclotriveratrylene product aTHOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLANDbROYAL SOC CHEMISTRYcDEC a2323-23290 v133 a

The inner-rim functionalization of CTV has been examined by employing Pd-catalyzed benzylic oxidation. The outcome of the oxidation depends upon the solvent and co-oxidants employed. An interesting array of CTV derivatives has been synthesized with a simple change in the conditions.

1 aSenthilkumar, B.1 aGonnade, Rajesh, G.1 aRamana, C., V. uhttp://library.ncl.res.in/content/pd-catalyzed-benzylic-c-h-oxidation-cyclotriveratrylene-product-diversity-001441nas a2200277 4500008004100000022001400041245013300055210006900188260006700257300001200324490000700336520045500343653002200798653002400820653001200844653002100856653002800877100002400905700002200929700001700951700002400968700001700992700001901009700001601028856011901044 2015 eng d a0899-004200aPreferential enrichment of DL-leucine using cocrystal formation with oxalic acid under nonequilibrium crystallization conditions0 aPreferential enrichment of DLleucine using cocrystal formation w a111 RIVER ST, HOBOKEN 07030-5774, NJ USAbWILEY-BLACKWELLcJUL a405-4100 v273 a

By utilizing the preferential enrichment (PE) technique, we achieved an improved enantiomeric resolution of DL-leucine (Leu) using a 1:1 cocrystal (DL-1) of DL-Leu and oxalic acid. The crystal structure analysis of DL-1 indicated the occurrence of a novel type of phase transition and subsequent preferential redissolution of one enantiomer from the resulting crystals into solution. Chirality 27:405-410 2015. (c) 2015 Wiley Periodicals, Inc.

10achiral resolution10acocrystal formation10aleucine10aphase transition10apreferential enrichment1 aManoj, Kochunnoonny1 aTakahashi, Hiroki1 aMorita, Yoko1 aGonnade, Rajesh, G.1 aIwama, Sekai1 aTsue, Hirohito1 aTamura, Rui uhttp://library.ncl.res.in/content/preferential-enrichment-dl-leucine-using-cocrystal-formation-oxalic-acid-under-001751nas a2200145 4500008004100000245005400041210005300095260000800148300001200156490000700168520130200175100002401477700001901501856008501520 2017 eng d00aPolymorphs and cocrystals: a comparative analysis0 aPolymorphs and cocrystals a comparative analysis cJUN a193-2260 v973 a

Controlling polymorphism has been the subject of vigorous research in the recent past in the pharmaceutical industry due to the distinct physicochemical properties associated with each solid form. Developing cocrystals/salts of active pharmaceutical ingredients (APIs) has gained tremendous research interest in recent years owing to their potential to improve pharmaceutically relevant properties without affecting therapeutic efficacy. It is observed that compounds that exhibit polymorphism and also contain several H bond donor/acceptor groups have a tendency to form cocrystals and sometime even display cocrystal polymorphism, although this tendency cannot be generalized. The aim of this contribution is to correlate crystal structures of some polymorphic APIs and their respective cocrystals to understand the rationale behind a polymorphic compound generating cocrystals. Here, we make an attempt to compare how the conformation of the molecule observed in its polymorphs support the generation of cocrystals/salts. We understand that it is impossible to cover all the polymorphs and their cocrystals/salts available in the CSD; the comparative study has been carried out with a few case studies, wherein APIs displayed polymorphism (conformation) and also formed cocrystals/salts.

1 aGonnade, Rajesh, G.1 aSangtani, Ekta uhttp://library.ncl.res.in/content/polymorphs-and-cocrystals-comparative-analysis02104nas a2200157 4500008004100000245010900041210006900150260000800219520149800227100001901725700001701744700001501761700002401776700001801800856012801818 2019 eng d00a Phosphite-Catalyzed C-H allylation of azaarenes via an enantioselective [2,3]-Aza-wittig rearrangement 0 aPhosphiteCatalyzed CH allylation of azaarenes via an enantiosele cAUG3 a

A phosphite-mediated [2,3]-aza-Wittig rearrangement has been developed for the regio- and enantioselective allylic alkylation of six-membered heteroaromatic compounds (azaarenes). The nucleophilic phosphite adducts of N-allyl salts undergo a stereoselective base-mediated aza-Wittig rearrangement and dissociation of the chiral phosphite for overall C-H functionalization of azaarenes. This method provides efficient access to tertiary and quaternary chiral centers in isoquinoline, quinoline, and pyridine systems, tolerating a broad variety of substituents on both the allyl part and azaarenes. Catalysis with chiral phosphites is also demonstrated with synthetically useful yields and enantioselectivities.

1 aMotaleb, Abdul1 aRani, Soniya1 aDas, Tamal1 aGonnade, Rajesh, G.1 aMaity, Pradip uhttp://library.ncl.res.in/content/phosphite-catalyzed-c-h-allylation-azaarenes-enantioselective-23-aza-wittig-rearrangement01140nas a2200181 4500008004100000022001400041245010400055210006900159260000900228300001400237490000700251520048000258100002100738700002700759700002400786700002400810856012400834 2020 eng d a1359-734500aPara-selective copper-catalyzed C(sp(2))-H amidation/dimerization of anilides via a radical pathway0 aParaselective coppercatalyzed Csp2H amidationdimerization of ani cFEB  a1565-15680 v563 a

Copper-catalyzed amidation/dimerization of anilides via regioselective C(sp(2))-H functionalization is achieved. The para-selective amidation is accomplished on the anilide aromatic ring via a radical pathway leading to C-N bond formation in the presence of ammonium persulfate as a radical source/oxidant for the copper catalyst. The developed protocol tolerates a wide range of anilide substrates. The regioselectivity is confirmed by single-crystal X-ray studies.

1 aViveki, Amol, B.1 aGarad, Dnyaneshwar, N.1 aGonnade, Rajesh, G.1 aMhaske, Santosh, B. uhttp://library.ncl.res.in/content/para-selective-copper-catalyzed-csp2-h-amidationdimerization-anilides-radical-pathway02235nas a2200253 4500008004100000022001400041245008000055210006900135260000900204300001200213490000700225520142200232653001001654653002201664653002901686653001701715653001701732100002401749700002501773700002401798700002401822700002401846856011101870 2020 eng d a1861-472800aPd-iminocarboxylate complexes and their behavior in ethylene polymerization0 aPdiminocarboxylate complexes and their behavior in ethylene poly cFEB  a398-4050 v153 a

Designing co-catalyst-free late transition metal complexes for ethylene polymerization is a challenging task at the interface of organometallic and polymer chemistry. Herein, a set of new, co-catalyst-free, single-component catalytic systems for ethylene polymerization have been unraveled. Treatment of anthranilic acid with various aldehydes produced four iminocarboxylate ligands (L1-L4) in very good to excellent yield (75-92 %). The existence of 2-((2-methoxybenzylidene)amino) benzoic acid (L1) has been unambiguously demonstrated using NMR spectroscopy, MS and single-crystal X-ray diffraction. A neutral Pd-iminocarboxylate complex [{N O}PdMe(L1)] (N O=kappa(2)-N,O-ArCHNC6H4CO2 with Ar=2-MeOC6H4) C1 was prepared by treating stoichiometric amount of L1.Na with palladium precursor. The identity of C1 was confirmed by 1-2D NMR spectroscopy and single-crystal X-ray diffraction studies. Along the same lines, palladium complexes C2-C4 were prepared from ligands L2-L4 respectively. In-situ high-pressure NMR investigations revealed that these Pd complexes are amenable to ethylene insertion and undergo facile beta-H elimination to produce propylene. These palladium complexes were then evaluated in ethylene polymerization reaction and various reaction parameters were screened. When C1-C4 were exposed to ethylene pressures of 10-50 bar, formation of low-molecular-weight polyethylene was observed.

10aimine10aImine-carboxylate10aInsertion polymerization10aPd complexes10aPolyethylene1 aDeshmukh, Satej, S.1 aGaikwad, Shahaji, R.1 aGonnade, Rajesh, G.1 aPandole, Satish, P.1 aChikkali, Samir, H. uhttp://library.ncl.res.in/content/pd-iminocarboxylate-complexes-and-their-behavior-ethylene-polymerization03088nas a2200181 4500008004100000245013200041210006900173260000800242300001400250490000700264520238600271100002502657700002402682700002502706700002002731700002402751856013102775 2021 eng d00aPolymorphs and hydrates of the anticancer drug erlotinib: X-ray crystallography, phase transition and biopharmaceutical studies0 aPolymorphs and hydrates of the anticancer drug erlotinib Xray cr cJUN a3961-39740 v233 a

Erlotinib, a non-small cell lung cancer BCS class II drug, was found to occur as two polymorphs and two hydrates depending on the crystallization conditions. The monohydrate (form III), which has been reported in patents and publications, is the preferred crystalline phase from solution crystallization. The other forms (polymorphs, forms I and II, and a trihydrate, form IV) are solvent and condition-specific. Form I was exclusively and reproducibly obtained from dried non-polar solvents (viz. toluene, benzene, and xylene) using a solution crystallization method under controlled conditions. In contrast, form II was obtained by the rotary evaporation technique under reduced pressure from polar solvents (viz. dichloromethane, ethyl acetate, acetone, and acetonitrile). Slow evaporation from polar and non-polar solvents under open conditions yielded form III crystals, whereas evaporation from acetone-acetonitrile-water mixtures yielded form IV crystals. DSC and variable temperature PXRD studies revealed form I to be the most stable phase while the other solid forms displayed thermally induced polymorphic transitions into form I crystals. Further, form I and form III are found to be stable over the 30-90% RH range. Further, form I displayed solution-mediated transformation into form III (monohydrate) when left to stand in the mother liquor for a longer duration (1-2 days). Similarly, the unstable form IV crystals transformed into the stable form III crystals within 1-2 h when exposed to an open atmosphere. Fast crystallization from polar solvents using the rotary evaporation technique enabled us to capture the metastable polymorph, form II. Early separation of form I from its mother liquor prevented its solution-mediated transformation into the monohydrate, form III. The water activity study revealed that form III is the most preferred solid phase in the presence of water. Dissolution rate measurements showed that the rate of form II is almost comparable to that of the marketed erlotinib hydrochloride. In contrast, for the other forms, the dissolution profiles showed a considerable decrease. Although the crystal structures of form I and form III have been published previously, this manuscript gives a comprehensive overview of the free base solid forms of erlotinib, the phase transitions amongst them and their biopharmaceutical properties.

1 aThorat, Shridhar, H.1 aGeorge, Christy, P.1 aShaligram, Parth, S.1 aSuresha, P., R.1 aGonnade, Rajesh, G. uhttp://library.ncl.res.in/content/polymorphs-and-hydrates-anticancer-drug-erlotinib-x-ray-crystallography-phase-transition-and02589nas a2200205 4500008004100000022001400041245011100055210006900166260000900235300001400244490000700258520185700265100002402122700002502146700001902171700001702190700002402207700002402231856012802255 2022 eng d a1528-748300aPolymorphs of green fluorescence protein chromophore analogue: fluorescence switching with thermal stimuli0 aPolymorphs of green fluorescence protein chromophore analogue fl cMAR  a1892-19050 v223 a

Polymorphs of fluorescent organic materials offer significant implications in optoelectronics and advanced materials as they modulate photoluminescence properties. A slight alteration in the conformation/packing of molecules in the crystals shows variation in photoluminescence. This necessitates the polymorph screening of these materials to develop novel crystalline forms with distinct fluorescence emissions for broader application. In continuation of our work on the polymorph screening of Green Fluorescence Protein Chromophore (GFPc), we have synthesized a new imidazoline derivative, ethyl (Z)-2-(2-methyl-5-oxo-4-(3,4,5-trimethoxybenzylidene)-4,5-dihydro-1H-imi dazol-1- yl)acetate (1). Polymorph screening of 1 under different crystallization conditions revealed three polymorphs, Form I (needle), Form II (block), and Form III (polycrystalline material). Forms I and II are the outcome of solution crystallization, whereas Form III was produced from the melt crystallization of Forms I and II. DSC, HSM, and powder and single-crystal XRD studies indicate the conversion of Form I and Form III crystals to Form II crystals on thermal stimuli. The photoluminescence studies revealed cyan, yellow, and yellowish-green fluorescence emission for Forms I, II, and III crystals, respectively. The difference in photoluminescence could be due to the variance in aggregation modes like H-aggregation in Form I and J-aggregation in Form II crystals. Form I, Form II, and Form III crystals also showed irreversible thermal fluorescent switching from cyan-yellow-green due to polymorphic phase transitions. The study correlates the direct observation of the modulation of the excited-state transition under thermal stimuli in the crystalline phase. It will help augment the pace in the research of thermally responsive fluorescent materials.

1 aMali, Bhupendra, P.1 aDash, Soumya, Ranjan1 aBiswas, Anupam1 aVanka, Kumar1 aManoj, Kochunnoonny1 aGonnade, Rajesh, G. uhttp://library.ncl.res.in/content/polymorphs-green-fluorescence-protein-chromophore-analogue-fluorescence-switching-thermal01288nas a2200181 4500008004100000022001400041245009300055210006900148260000800217300001400225490000700239520065100246100002600897700002200923700002400945700002000969856011700989 2023 eng d a1523-706000aPalladium-catalyzed chemoselective oxygenation of C(sp2)-H and C(sp3)-H bonds in isatins0 aPalladiumcatalyzed chemoselective oxygenation of Csp2H and Csp3H cMAR a1862-18670 v253 a

The palladium-catalyzed chemoselective C(sp2)-H and C(sp3)-H bond oxygenation of substituted isatin derivatives is reported. This mild protocol exhibits the C5 C(sp2)-H oxygenation of isatins through electrophilic intermolecular C-H palladation in concentrated solutions using PhI(OAc)2 or Selectfluor as an oxidant, whereas it exhibits- N-CH3 C(sp3)-H oxygenation in dilute solutions via carbonyl-assisted intramolecular palladation in the presence of K2S2O8. This oxygenation reaction provides a direct and unified approach for synthesizing diverse oxygenated isatins with sensitive functionalities, including biorelevant compounds.

1 aVijaykumar, Muniyappa1 aPradhan, Chandini1 aGonnade, Rajesh, G.1 aPunji, Benudhar uhttp://library.ncl.res.in/content/palladium-catalyzed-chemoselective-oxygenation-csp2-h-and-csp3-h-bonds-isatins02262nas a2200217 4500008004100000022001400041245011800055210006900173260000800242300001400250490000700264520147700271100002701748700002401775700002701799700001901826700002201845700002301867700002401890856013001914 2023 eng d a1759-995400aPalladium-catalyzed polar solvent empowered synthesis of hyper-branched ethylene oligomers and their applications0 aPalladiumcatalyzed polar solvent empowered synthesis of hyperbra cJUL a3239-32510 v143 a

In this contribution, we report the synthesis of two naphthoxy imine ligands, 2-(((2,6-dibenzhydryl-4-methoxyphenyl)imino)methyl)naphthalen-1-ol (L1) and 2-(((2,6-diisopropylphenyl)imino)methyl)naphthalen-1-ol (L2), with different steric and electronic features. L1 and L2 were treated with [(TMEDA)PdMe2] to obtain the corresponding neutral palladium(ii) complexes Cat.1 and Cat.2 in excellent yields. The identity of Cat.1 and Cat.2 was unambiguously ascertained using a combination of spectroscopic and analytical methods, including single-crystal X-ray diffraction. When exposed to 5 bar ethylene pressure, Cat.1 produced hyperbranched ethylene oligomers. The microstructure analysis of ethylene oligomers confirmed the existence of methyl, ethyl, propyl, and sec-butyl branches, with a molecular weight (M-n) of 500-1400 g mol(-1), a PDI of 1.46-2.10, and 67-106 branches per 1000 carbon atoms. The use of a polar solvent, tetrahydrofuran, led to a remarkable 3-fold increase in oligomerization activity without compromising the branching and molecular weight. The resultant hyperbranched ethylene oligomers were selectively monofunctionalized using industrially practiced hydroformylation, ozonolysis, and epoxidation, almost quantitatively. The hydroxy functionalized ethylene oligomer (F4) (5 wt%) was melt-compounded with LLDPE and Nylon-6 to produce a tough yet flexible blend with a higher strain-to-failure as compared to an uncompatibilized blend.

1 aBirajdar, Rajkumar, S.1 aGonnade, Rajesh, G.1 aPol, Harshawardhan, V.1 aPrabhu, Basava1 aRokade, Dhammaraj1 aNandimath, Sheetal1 aChikkali, Samir, H. uhttp://library.ncl.res.in/content/palladium-catalyzed-polar-solvent-empowered-synthesis-hyper-branched-ethylene-oligomers-and00975nas a2200193 4500008004100000245006800041210006800109260000800177300001400185490000700199520034000206100001900546700001900565700002600584700002400610700002400634700002400658856009900682 2023 eng d00aPolymorph II of hydroxyurea 150 years after its first synthesis0 aPolymorph II of hydroxyurea 150 years after its first synthesis cMAY a2712-27160 v253 a

A new polymorph of hydroxyurea (HU) was crystallized 150 years after its first synthesis. Due to its medicinal use in neoplastic diseases and sickle cell anemia, a high throughput screen of HU binary cocrystals was attempted. Instead of a cocrystal, an isoenergetic form II crystallized concomitantly with urea in methanol.

1 aRai, Sunil, K.1 aTothadi, Srinu1 aArhangelskis, Mihails1 aGeorge, Christy, P.1 aGonnade, Rajesh, G.1 aNangia, Ashwini, K. uhttp://library.ncl.res.in/content/polymorph-ii-hydroxyurea-150-years-after-its-first-synthesis00974nas a2200277 4500008004100000022001400041245013800055210006900193260000800262490000600270653000800276653001500284653001800299653001900317100003000336700002300366700002500389700001900414700002500433700002400458700002100482700001800503700002000521700002400541856013100565 2024 eng d a2365-654900aPyridazine-Based Aggregation Induced Emission Active Conjugates: Synthesis, Single Crystal XRD Analysis, and Self-Assembly Assessment0 aPyridazineBased Aggregation Induced Emission Active Conjugates S cOCT0 v910aAIE10aPyridazine10aSelf-assembly10aSingle crystal1 aWaghchoure, Aishwarya, P.1 aSangale, Vijay, B.1 aShaligram, Parth, S.1 aLambud, Sushil1 aPardeshi, Satish, K.1 aGonnade, Rajesh, G.1 aBandaru, Sateesh1 aMore, Sandeep1 aReddy, Prakasha1 aBhosale, Rajesh, S. uhttp://library.ncl.res.in/content/pyridazine-based-aggregation-induced-emission-active-conjugates-synthesis-single-crystal-xrd02020nas a2200217 4500008004100000022001400041245011000055210006900165260000800234490000700242520126500249653001901514653001201533653001401545653001901559653002601578100002601604700002401630700002001654856012801674 2025 eng d a1867-388000aPalladium-catalyzed regioselective C(4)-H fluoroalkoxylation of indoles through weak chelation assistance0 aPalladiumcatalyzed regioselective C4H fluoroalkoxylation of indo cJAN0 v173 a

Installing fluoroalkyl motifs into biorelevant indoles is particularly interesting due to their ubiquitous presence in drug molecules. Herein, we demonstrate the regioselective C4 fluoroalkoxylation of indoles using fluoroalcohols via palladium-catalyzed chelation-assisted C & horbar;H activation. The weak chelating benzoyl moiety at the C3 position acts as a directing group for remote C(4)& horbar;H fluoroalkoxylation of diversely substituted indoles. This methodology demonstrates a high level of regioselectivity and tolerates a range of crucial functional groups, yielding diverse trifluoroalkoxylated indoles in moderate to good yields. Removal of directing/protecting groups and further functionalization established the synthetic utility of the methodology. A preliminary mechanistic investigation is conducted by isolating the palladacycle intermediate and performing the deuterium scrambling study. The regioselective C4 fluoroalkoxylation of indoles with various fluoroalcohols is achieved by the palladium-catalyzed weak chelation assistance strategy. The reaction is compatible for a range of important functionalities and proceeds via the intermediacy of a six-membered palladacycle following a Pd(II)/Pd(IV) pathway. image

10aC-H activation10aindoles10aPalladium10aRegioselective10aTrifluoroalkoxylation1 aVijaykumar, Muniyappa1 aGonnade, Rajesh, G.1 aPunji, Benudhar uhttp://library.ncl.res.in/content/palladium-catalyzed-regioselective-c4-h-fluoroalkoxylation-indoles-through-weak-chelation