01382nas a2200169 4500008004100000245008000041210006900121260000800190300001800198490000800216520078100224100002501005700002801030700002501058700002001083856010901103 2010 eng d00aDirect hydrogenation of amides to alcohols and amines under mild conditions0 aDirect hydrogenation of amides to alcohols and amines under mild cNOV a16756–167580 v1323 a

The selective, direct hydrogenation of amides to the corresponding alcohols and amines with cleavage of the C−N bond was discovered. The expected products of C−O cleavage are not formed (except as traces in the case of anilides). The reaction proceeds under mild pressure and neutral, homogeneous conditions using a dearomatized, bipyridyl-based PNN Ru(II) pincer complex as a catalyst. The postulated mechanism involves metal−ligand cooperation by aromatization−dearomatization of the heteroaromatic pincer core and does not involve hydrolytic cleavage of the amide. The simplicity, generality, and efficiency of this environmentally benign process make it attractive for the direct transformations of amides to alcohols and amines in good to excellent yields.

1 aBalaraman, Ekambaram1 aGnanaprakasam, Boopathy1 aShimon, Linda, J. W.1 aMilstein, David uhttps://library.ncl.res.in/content/direct-hydrogenation-amides-alcohols-and-amines-under-mild-conditions01100nas a2200169 4500008004100000245015500041210006900196260000800265300001800273490000800291520040300299100002800702700002500730700002400755700002000779856013100799 2011 eng d00aSynthesis of peptides and pyrazines from beta-aminoalcohols via extrusion of H2 catalyzed by ruthenium pincer complexes. ligand controlled selectivity0 aSynthesis of peptides and pyrazines from betaaminoalcohols via e cOCT a12448–124520 v1233 a

Bitte wählen: Die Wahl des Katalysators, eines Ru-Pinzettenkomplexes, bestimmt, ob Peptide oder Pyrazine aus β-Aminoalkoholen entstehen: Der PNN-Komplex 1 führt, je nach Substituent R (siehe Schema), zu linearem Polyalanin oder zu cyclischen Dipeptiden, der PNP-Komplex 2 katalysiert die Bildung von Pyrazinen. Die Reaktionen finden in homogener Lösung unter neutralen Bedingungen statt.

1 aGnanaprakasam, Boopathy1 aBalaraman, Ekambaram1 aBen-David, Yehoshoa1 aMilstein, David uhttps://library.ncl.res.in/content/synthesis-peptides-and-pyrazines-beta-aminoalcohols-extrusion-h2-catalyzed-ruthenium-pincer01874nas a2200157 4500008004100000245013500041210006900176260000800245520121900253100002001472700002501492700002801517700002801545700001601573856012701589 2012 eng d00aNovel ruthenium complexes and their uses in processes for formation and/or hydrogenation of esters, amides and derivatives thereof0 aNovel ruthenium complexes and their uses in processes for format cOCT3 a

The present invention relates to novel Ruthenium complexes and related borohydride complexes, and their use for (1) hydrogenation of amides (including polyamides) to alcohols and amines; (2) preparing amides from alcohols with amines (including preparing polyamides (e.g., polypeptides) by reacting dialcohols and diamines or by polymerization of amino alcohols); (3) hydrogenation of esters to alcohols (including hydrogenation of cyclic esters (lactones), cyclic di-esters (di-lactones) or polyesters); (4) hydrogenation of organic carbonates (including polycarbonates) to alcohols and of carbamates (including polycarbamates) or urea derivatives to alcohols and amines; (5) dehydrogenative coupling of alcohols to esters; (6) hydrogenation of secondary alcohols to ketones; (7) amidation of esters (synthesis of amides from esters and amines); (8) acylation of alcohols using esters; (9) coupling of alcohols with water to form carboxylic acids; and (10) dehydrogenation of beta-amino alcohols to form pyrazines. The present invention further relates to novel uses of certain pyridine Ruthenium complexes.

1 aMilstein, David1 aBalaraman, Ekambaram1 aGunanathan, Chidambaram1 aGnanaprakasam, Boopathy1 aZhang, Jing uhttps://library.ncl.res.in/content/novel-ruthenium-complexes-and-their-uses-processes-formation-andor-hydrogenation-esters00981nas a2200181 4500008004100000245013100041210006900172260000800241300001600249490000800265520028300273100002200556700002500578700002800603700002400631700002000655856012400675 2012 eng d00aRuthenium pincer-catalyzed cross-dehydrogenative coupling of primary alcohols with secondary alcohols under neutral conditions0 aRuthenium pincercatalyzed crossdehydrogenative coupling of prima cSEP a2403–24060 v3543 a

Cross-dehydrogenative coupling of primary alcohols with secondary alcohols to obtain mixed esters with the liberation of molecular hydrogen is achieved in high yield and good selectivity under neutral conditions, using a bipyridyl-based PNN ruthenium(II) pincer catalyst.

1 aSrimani, Dipankar1 aBalaraman, Ekambaram1 aGnanaprakasam, Boopathy1 aBen-David, Yehoshoa1 aMilstein, David uhttps://library.ncl.res.in/content/ruthenium-pincer-catalyzed-cross-dehydrogenative-coupling-primary-alcohols-secondary02002nas a2200169 4500008004100000245007400041210006900115260000800184300001600192490000700208520142300215100002801638700002501666700002801691700002001719856009301739 2012 eng d00aSynthesis of polyamides from diols and diamines with liberation of H20 aSynthesis of polyamides from diols and diamines with liberation  cMAY a1755–17650 v503 a

The amidation reaction based on catalytic coupling of alcohols with amines previously reported by us, using the pincer complexes 1 and 2 as catalysts, was applied to the generation of polyamides from nonactivated diols and diamines. A range of polymers was prepared, with Mn up to 26.9 kDa. Unlike the traditional syntheses of polyamides based on carboxylic acid derivatives, which require the use of toxic reagents and generate stoichiometric amounts of waste, this process generates only molecular hydrogen as byproduct. Both aromatic and aliphatic diols and diamines were used. Gel permeation chromatography measurements of the dimethylformamide-soluble polymers and thermal studies of the polyamides were performed. Matrix assisted laser desorption/ionization time-of-flight (MALDI-TOF) spectra are also reported. Thermogravimetric analyses studies indicate that the aromatic polyamides (with the exception of the pyridine-based polyamide) are more thermally stable than the aliphatic ones. This general, environmentally benign method for the synthesis of polyamides is homogeneously catalyzed under neutral conditions by dearomatized ruthenium-pincer complexes 1 and 2 and proceeds in 1,4-dioxane under an inert atmosphere. Conditions for polyamidation in the absence of solvent are also reported, using the pincer complex 2 as catalyst. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012

1 aGnanaprakasam, Boopathy1 aBalaraman, Ekambaram1 aGunanathan, Chidambaram1 aMilstein, David uhttps://library.ncl.res.in/content/synthesis-polyamides-diols-and-diamines-liberation-h201646nas a2200169 4500008004100000245011600041210006900157260000800226520097300234100002001207700002801227700002401255700002501279700002801304700001601332856012801348 2012 eng d00aUse of ruthenium complexes for formation and/or hydrogenation of amides and related carboxylic acid derivatives0 aUse of ruthenium complexes for formation andor hydrogenation of  cMAR3 a

A process for preparing amides by reacting a primary amine and a primary alcohol in the presence of a Ruthenium complex to generate the amide and molecular hydrogen. Primary amines are directly acylated by equimolar amounts of alcohols to produce amides and molecular hydrogen (the only byproduct) in high yields and high turnover numbers. Also disclosed are processes for hydrogenation of amides to alcohols and amines; hydrogenation of organic carbonates to alcohols; hydrogenation of carbamates or urea derivatives to alcohols and amines; amidation of esters; acylation of alcohols using esters; coupling of alcohols with water and a base to form carboxylic acids; dehydrogenation of beta-amino alcohols to form pyrazines and cyclic dipeptides; and dehydrogenation of secondary alcohols to ketones. These reactions are catalyzed by a Ruthenium complex which is based on a dearomatized PNN-type ligand of formula A1 or precursors thereof of formulae A2 or A3.

1 aMilstein, David1 aGunanathan, Chidambaram1 aBen-David, Yehoshoa1 aBalaraman, Ekambaram1 aGnanaprakasam, Boopathy1 aZhang, Jing uhttps://library.ncl.res.in/content/use-ruthenium-complexes-formation-andor-hydrogenation-amides-and-related-carboxylic-acid01623nas a2200145 4500008004100000245012200041210006900163260000800232520100300240100002501243700002401268700002801292700002801320856012901348 2019 eng d00aMnO2@Fe3O4 Magnetic Nanoparticles as Efficient and Recyclable Heterogeneous Catalyst for Benzylic sp(3) C-H Oxidation0 aMnO2Fe3O4 Magnetic Nanoparticles as Efficient and Recyclable Het cSEP3 a

Herein, we report a highly chemoselective and efficient heterogeneous MnO2@Fe3O4 MNP catalyst for the oxidation of benzylic sp(3) C-H group of ethers using TBHP as a green oxidant to afford ester derivatives in high yield under batch/continuous flow module. This catalyst was also effective for the benzylic sp(3) C-H group of methylene derivatives to furnish the ketone in high yield which can be easily integrated into continuous flow condition for scale up. The catalyst is fully characterized by spectroscopic techniques and it was found that 0.424 % MnO2@Fe3O4 catalyzes the reaction; the magnetic nanoparticles of this catalyst could be easily recovered from the reaction mixture. The recovered catalyst was recycled for twelve cycles without any loss of the catalytic activity. The advantages of MnO2@Fe3O4 MNP are its catalytic activity, easy preparation, recovery, and recyclability, gram scale synthesis with a TOF of up to 14.93 h(-1) and low metal leaching during the reaction.

1 aPandey, Akanksha, M.1 aAgalave, Sandip, G.1 aVinod, Chathakudath, P.1 aGnanaprakasam, Boopathy uhttps://library.ncl.res.in/content/mno2fe3o4-magnetic-nanoparticles-efficient-and-recyclable-heterogeneous-catalyst-benzylic01549nas a2200193 4500008004100000022001400041245011000055210006900165260000900234300001600243490000700259520084100266100002301107700002901130700002101159700002601180700002801206856012101234 2022 eng d a0022-326300aLewis acid-catalyzed chemodivergent and regiospecific reaction of phenols with quaternary peroxyoxindoles0 aLewis acidcatalyzed chemodivergent and regiospecific reaction of cNOV  a14155-141670 v873 a

The indium-catalyzed regiospecific coupling of substituted phenol derivatives and quaternary peroxyoxindoles for the synthesis of C2 or C4 benzoxazin-3-one-substituted phenols via skeletal rearrangement is described. This reaction is demonstrated with 17 examples with good yields and diverse aryl substituents. In contrast to the indium-catalyzed reaction, the Cu(OTf)2- catalyzed reaction of the phenol with quaternary peroxyoxindoles afforded C2 or C4 2-oxindole-substituted phenol derivatives. This diverse catalytic reaction generated various biologically important phenol-substituted 2-oxindole derivatives directly without any skeleton rearrangement and was demonstrated with 19 examples in high yield. The regiospecificity and the reaction pathways were explained with the support of density functional theory (DFT).

1 aShaikh, Moseen, A.1 aSamal, Pragnya, Paramita1 aUbale, Akash, S.1 aKrishnamurty, Sailaja1 aGnanaprakasam, Boopathy uhttps://library.ncl.res.in/content/lewis-acid-catalyzed-chemodivergent-and-regiospecific-reaction-phenols-quaternary01682nas a2200205 4500008004100000022001400041245011900055210006900174260000800243300001400251490000700265520092200272100002101194700002901215700002501244700002301269700002601292700002801318856013001346 2023 eng d a0022-326300aCatalyst-assisted selective vinylation and methylallylation of a quaternary carbon center using tert-butyl acetate0 aCatalystassisted selective vinylation and methylallylation of a  cJUL a9686-97030 v883 a

The In-(OTf)(3)-catalyzed & alpha;-vinylationof varioushydroxy-functionalized quaternary carbon centers using in situ generatedisobutylene from tert-butyl acetate is presentedas a novel synthetic methodology. Moreover, tert-butylacetate is a nonflammable feed stock and is a readily available sourcefor the in situ production of vinyl substituents, as demonstratedby the vinylation reaction with quaternary hydroxy/methoxy compounds.Moreover, an excellent selectivity for methylallylation over vinylationwas obtained with Ni-(OTf)(2) as a catalyst. In the case ofperoxyoxindole, methylallyl-functionalized 1,4-benzoxazin-3-one derivativeswere formed through the sequential rearrangement of peroxyoxindolefollowed by the nucleophilic attack by isobutylene. The detailed mechanismfor this reaction and rationalization for the selectivity are providedusing kinetics and density functional theory studies.

1 aMohanta, Nirmala1 aSamal, Pragnya, Paramita1 aPandey, Akanksha, M.1 aMondal, Shankhajit1 aKrishnamurty, Sailaja1 aGnanaprakasam, Boopathy uhttps://library.ncl.res.in/content/catalyst-assisted-selective-vinylation-and-methylallylation-quaternary-carbon-center-using01178nas a2200253 4500008004100000022001400041245008400055210006900139260000800208300001200216490000800228520038000236653000600616653002400622653001000646653001900656653001800675653001900693100002100712700002700733700002600760700002800786856011000814 2023 eng d a1615-415000aFeCl2-catalyzed rearrangement of aryl peroxyoxindole into 1,3-benzooxazin-4-One0 aFeCl2catalyzed rearrangement of aryl peroxyoxindole into 13benzo cFEB a515-5210 v3653 a

We report an FeCl2-catalyzed radical rearrangement of aryl peroxyoxindoles into 1,3-benzooxazin-2-ones to obtain a variety of aryl substituted 1,3-benzooxazin-4-ones in moderate to good yields. Mechanistically, this skeletal rearrangement of peroxyoxindoles proceeded via radical pathway and was well supported with a series of experimental findings and DFT studies.

10a110a3-Benzooxazin-4-one10aFeCl210aPeroxyoxindole10arearrangement10aRing expansion1 aMohanta, Nirmala1 aSamal, PragnyaParamita1 aKrishnamurty, Sailaja1 aGnanaprakasam, Boopathy uhttps://library.ncl.res.in/content/fecl2-catalyzed-rearrangement-aryl-peroxyoxindole-13-benzooxazin-4-one02330nas a2200217 4500008004100000022001400041245020900055210007000264260000800334490000700342520144700349653002001796653002401816653002601840653002501866653002601891100001801917700001801935700002801953856013101981 2025 eng d a2193-580700aContinuous flow β-zeolite catalysed regioselective alkylation of naphthols using alcohols for synthesis of peroxynaphthalen-2(1H)-one, Azidonaphthalen-2(1H)-one and Fluoronaphthalen-2(1H)-one derivatives0 aContinuous flow βzeolite catalysed regioselective alkylation of  cAPR0 v143 a

Functionalized naphthols are prominent scaffolds in organic synthesis and materials chemistry. Herein, we demonstrated continuous flow alkylation of alpha- and beta-naphthols by using various primary and secondary benzylic alcohols in the presence of environmentally benign granular beta-zeolite as a reusable catalyst. For a variety of beta-naphthols, the respective alkylated products with good regioselectivity were obtained in high yields under mild reaction conditions. This protocol proceeded via the classical Friedel-Crafts type alkylation process and generated stable carbocations as intermediates. Applying this protocol, versatile naphthol derivatives have been synthesized using primary and secondary benzylic alcohols (50 and 44 examples in batch and continuous flow process, respectively), with good yields. Key advantages of this process includes rapid and efficient transformation, facilitates gram-scale synthesis, and generates water as the sole by-product. The most significant advantage is the continuous reusability of granular beta-zeolite, which further emphasizes the sustainability of the method. The application of alkylated naphthols for quaternary functionalization was demonstrated through peroxidation, azidation, and halogenation reactions under the continuous flow module, which yielded the respective peroxynaphthalen-2(1H)-one, azidonaphthalen-2(1H)-one and fluoronaphthalen2(1H)-one derivatives.

10acontinuous flow10aMultigram Synthesis10aReusable beta-zeolite10aSustainable Appraoch10aTransition metal free1 aLondhe, Gokul1 aBokade, Vijay1 aGnanaprakasam, Boopathy uhttps://library.ncl.res.in/content/continuous-flow-%CE%B2-zeolite-catalysed-regioselective-alkylation-naphthols-using-alcohols