01502nas a2200229   4500008004100000022001400041245011900055210006900174260010600243300001400349490000700363520058100370653003000951653002700981653002701008653001101035653002501046100002301071700002401094700002201118856013201140       2013                        eng d  a0040-403900aN-Heterocyclic carbene catalyzed oxidative stannylation of aldehydes: a facile entry to organotin(IV) carboxylates0 aNHeterocyclic carbene catalyzed oxidative stannylation of aldehy  aTHE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLANDbPERGAMON-ELSEVIER SCIENCE LTDcMAY  a2679-26810 v543 a<p>A simple protocol is described for the oxidative transformation of aldehydes to the corresponding organotin(IV) carboxylates in high yields (up to 90%) that utilizes atmospheric O-2 as the sole oxidant, N-heterocyclic carbene as catalyst (at 10 mol %), and tributyl tin chloride as stannylating agent. The uniqueness of the reaction lies in the direct conversion of aldehydes to the corresponding organotin(IV) carboxylates via stannylation of carboxylic acids, generated from the reaction of a Breslow intermediate with O-2. (c) 2013 Elsevier Ltd. All rights reserved.</p>10aCarboxylic acid stannanes10aN-Heterocyclic carbene10aOxidative stannylation10aoxygen10aTributyltin chloride1 aReddi, Rambabu, N.1 aMalekar, Pushpa, V.1 aSudalai, Arumugam  uhttps://library.ncl.res.in/content/n-heterocyclic-carbene-catalyzed-oxidative-stannylation-aldehydes-facile-entry-organotiniv-001149nas a2200169   4500008004100000022001400041245016500055210006900220260011000289300001400399490000700413520036600420100002300786700002400809700002200833856012400855       2013                        eng d  a1477-052000aN-Heterocyclic carbene catalyzed regioselective oxo-acyloxylation of alkenes with aromatic aldehydes: a high yield synthesis of alpha-acyloxy ketones and esters0 aNHeterocyclic carbene catalyzed regioselective oxoacyloxylation   aTHOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLANDbROYAL SOC CHEMISTRYcOCT  a6477-64820 v113 a<p>An N-heterocyclic carbene (NHC)-catalyzed reaction of alkenes with aromatic aldehydes providing for a high yield synthesis of alpha-acyloxy ketones and esters has been described. This unprecedented regioselective oxidative process employs NBS and Et3N in stoichiometric amounts and O-2 (1 atm) as an oxidant under ambient conditions in DMSO as a solvent.</p>1 aReddi, Rambabu, N.1 aMalekar, Pushpa, V.1 aSudalai, Arumugam  uhttps://library.ncl.res.in/content/n-heterocyclic-carbene-catalyzed-regioselective-oxo-acyloxylation-alkenes-aromatic-001266nas a2200169   4500008004100000022001400041245016200055210006900217260007100286300001400357490000700371520051800378100002300896700002400919700002200943856013100965       2014                        eng d  a1523-706000aI-2-catalyzed regioselective Oxo- and hydroxy-acyloxylation of alkenes and enol ethers: a facile access to alpha-acyloxyketones, esters, and diol derivatives0 aI2catalyzed regioselective Oxo and hydroxyacyloxylation of alken  a1155 16TH ST, NW, WASHINGTON, DC 20036 USAbAMER CHEMICAL SOCcNOV  a5674-56770 v163 a<p>I-2-catalyzed oxo-acyloxylation of alkenes and enol ethers with carboxylic acids providing for the high yield synthesis of a-acyloxyketones and esters is described. This unprecedented regioselective oxidative process employs TBHP and Et3N in stoichiometric amounts under metal-free conditions in DMSO as solvent. Additionally, I-2-catalysis allows the direct hydroxy-acyloxylation of alkenes with the sequential addition of BH3 center dot SMe2 leading to monoprotected diol derivatives in excellent yields.</p>1 aReddi, Rambabu, N.1 aPrasad, Pragati, K.1 aSudalai, Arumugam  uhttps://library.ncl.res.in/content/i-2-catalyzed-regioselective-oxo-and-hydroxy-acyloxylation-alkenes-and-enol-ethers-facile-001204nas a2200229   4500008004100000022001400041245015100055210006900206260007500275300001600350490000700366520031300373653001400686653001600700653002800716653001400744653002200758100002300780700002400803700002200827856012500849       2015                        eng d  a1433-785100aN-Heterocyclic carbene catalyzed oxidative coupling of alkenes/alpha-bromoacetophenones with aldehydes: a facile entry to alpha,beta-epoxy ketones0 aNHeterocyclic carbene catalyzed oxidative coupling of alkenesalp  aPOSTFACH 101161, 69451 WEINHEIM, GERMANYbWILEY-V C H VERLAG GMBHcNOV  a14150-141530 v543 a<p>{A novel, N-heterocyclic carbene (NHC) catalyzed direct oxidative coupling of styrenes with aldehydes has been described for the synthesis of alpha,beta-epoxy ketones in good yields. This unprecedented regioselective oxidative coupling employs NBS/DBU/DMSO (DBU = 1,8-diazabicyclo [5.4. 0] undec-7-ene</p>10aaldehydes10aepoxidation10aN-heterocyclic carbenes10aOxidation10asynthetic methods1 aReddi, Rambabu, N.1 aPrasad, Pragati, K.1 aSudalai, Arumugam  uhttps://library.ncl.res.in/content/n-heterocyclic-carbene-catalyzed-oxidative-coupling-alkenesalpha-bromoacetophenones-101046nas a2200193   4500008004100000022001400041245005700055210005400112260011000166300001400276490000700290520034600297100002400643700002600667700002300693700002300716700002200739856009100761       2016                        eng d  a1477-052000aI-2-mediated regioselective C-3 azidation of indoles0 aI2mediated regioselective C3 azidation of indoles  aTHOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLANDbROYAL SOC CHEMISTRYcFEB  a3027-30300 v143 a<p>An unprecedented synthesis of novel 3-azido indoles has been developed using I-2 and NaN3 in high yields and excellent regio-selectivity. The reaction proceeds under metal-free conditions at room temperature. Essentially, an umpolung in reactivity at the C-3 position of indole has been achieved by the activation of indoles with I-2.</p>1 aPrasad, Pragati, K.1 aKalshetti, Rupali, G.1 aReddi, Rambabu, N.1 aKamble, Sanjay, P.1 aSudalai, Arumugam  uhttps://library.ncl.res.in/content/i-2-mediated-regioselective-c-3-azidation-indoles-001257nas a2200241   4500008004100000022001400041245015100055210006900206260007500275300001000350490000600360520034400366653001400710653001300724653002100737653002800758653001100786100002300797700001900820700002400839700002200863856013000885       2016                        eng d  a2193-580700aN-heterocyclic-carbene-catalyzed regioselective oxidative ring-opening of epoxides with aromatic aldehydes: a facile entry to alpha-acyloxyketones0 aNheterocycliccarbenecatalyzed regioselective oxidative ringopeni  aPOSTFACH 101161, 69451 WEINHEIM, GERMANYbWILEY-V C H VERLAG GMBHcJAN  a48-510 v53 a<p>A high-yielding synthesis of -acyloxyketones using a N-heterocyclic-carbene (NHC)-catalyzed, oxidative ring-opening of epoxides with aromatic aldehydes is described. This regioselective, oxidative process utilizes a N-bromosuccinimide (NBS)/DMSO combination as the oxidant system and Et3N as the base under mild reaction conditions.</p>10aaldehydes10aepoxides10ahalogen oxidants10aN-heterocyclic carbenes10aoxygen1 aReddi, Rambabu, N.1 aGontala, Arjun1 aPrasad, Pragati, K.1 aSudalai, Arumugam  uhttps://library.ncl.res.in/content/n-heterocyclic-carbene-catalyzed-regioselective-oxidative-ring-opening-epoxides-aromatic-001363nas a2200169   4500008004100000022001400041245016900055210006900224260007100293300001200364490000700376520060900383100002400992700002301016700002201039856013201061       2016                        eng d  a1523-706000aRegioselective oxo-amination of alkenes and enol ethers with N-bromosuccinimide-dimethyl sulfoxide combination: a facile synthesis of alpha-amino-ketones and esters0 aRegioselective oxoamination of alkenes and enol ethers with Nbro  a1155 16TH ST, NW, WASHINGTON, DC 20036 USAbAMER CHEMICAL SOCcFEB  a500-5030 v183 a<p>An unprecedented conversion of alkenes and enol ethers to the corresponding a-imido carbonyl compounds with excellent regioselectivity and yields has been developed. This oxo-amination process employs readily available N-bromosuccinimide (NBS) and secondary amines as N-sources and dimethyl sulfoxide (DMSO) as the oxidant and also leads to the production of amino alcohols in a single step on reduction, thus broadening the scope of this operationally simple reaction. For the first time, the formation of reactive Me2S+-O-Br species generated by the interaction of NBS with DMSO has been proven.</p>1 aPrasad, Pragati, K.1 aReddi, Rambabu, N.1 aSudalai, Arumugam  uhttps://library.ncl.res.in/content/regioselective-oxo-amination-alkenes-and-enol-ethers-n-bromosuccinimide-dimethyl-sulfoxide-001245nas a2200169   4500008004100000245018100041210006900222260000800291300001200299490000700311520053800318100002300856700002400879700002600903700002200929856012400951       2017                        eng d00aConcise enantioselective synthesis of 1,4-dideoxy-1,4-imino-D-arabinitol using Co(III)(salen)-catalyzed hydrolytic kinetic resolution of a two-stereocentered anti-azido epoxide0 aConcise enantioselective synthesis of 14dideoxy14iminoDarabinito  cJAN  a162-1650 v283 aA concise enantioselective synthesis of 1,4-dideoxy-1,4-imino-D-arabinitol, (+)-DAB-1, has been described in good overall yield (18.1%) and with high enantiomeric purity (up to 98% ee) starting from a simple raw material, cis-2-butene-1,4-diol. The Co-catalyzed hydrolytic kinetic resolution of a two-stereocentered racemic azido epoxide followed by asymmetric dihydroxylation of the alkene and 'one pot' reductive cyclisation of the azido diol are key reactions in the synthetic sequence. (C) 2016 Elsevier Ltd. All rights reserved.1 aReddi, Rambabu, N.1 aPrasad, Pragati, K.1 aKalshetti, Rupali, G.1 aSudalai, Arumugam  uhttps://library.ncl.res.in/content/concise-enantioselective-synthesis-14-dideoxy-14-imino-d-arabinitol-using-coiiisalen01587nas a2200229   4500008004100000022001400041245015600055210006900211260000800280300001400288490000700302520073500309653002101044653002001065653001401085653003501099653003501134100002301169700002201192700001701214856012601231       2022                        eng d  a0253-296400aStudies toward the total synthesis of (+)-neopeltolide using N-heterocyclic carbene-catalyzed oxo-acyloxylation/reductive oxa-Michael addition strategy0 aStudies toward the total synthesis of neopeltolide using Nhetero  cOCT  a1169-11720 v433 a<p>
	This article describes a concise synthesis of two important fragments (tetrahydropyran [THP] and ketone moieties) of the cytotoxic macrolide (+)-neopeltolide in 10 long linear steps in enantiomerically pure form. Asymmetric Keck allylation to install the required C11 and C13 stereocenters, N-heterocyclic carbene (NHC)-catalyzed oxoacyloxylation to functionalize alkenes, and reductive oxa-Michael addition to construct 2,6-difunctionalized THP unit intramolecularly are the important steps in synthetic efforts. Finally, Keck asymmetric allylation and Lewis acid-catalyzed diastereoselective allylation of the aldehyde were sequentially employed to establish the stereocenters at C11 and C13 positions, respectively.</p>
10a(+)-neopeltolide10aKeck allylation10aMacrolide10aNHC-catalyzed oxoacyloxylation10areductive oxa-Michael addition1 aReddi, Rambabu, N.1 aSudalai, Arumugam1 aJo, Changbum  uhttps://library.ncl.res.in/content/studies-toward-total-synthesis-neopeltolide-using-n-heterocyclic-carbene-catalyzed-oxo