01005nas a2200157   4500008004100000022001400041245006100055210005900116260010600175300001400281490000700295520039600302100002600698700002800724856009500752       2006                        eng d  a0957-416600aSyntheses and applications of C-2-symmetric chiral diols0 aSyntheses and applications of C2symmetric chiral diols  aTHE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLANDbPERGAMON-ELSEVIER SCIENCE LTDcAUG  a1901-19290 v173 a<p>Synthetic procedures for a large variety of C-2-symmetric chiral diols are reviewed. Prominent among these procedures are enantioselective reductions, epoxide-cleavages, dihydroxylation of olefins, and synthetic transformations. Applications of these diols as chiral auxiliaries/ligands for several important reactions are also highlighted. (c) 2006 Elsevier Ltd. All rights reserved.</p>1 aBhowmick, Kartick, C.1 aJoshi, Navalkishore, N.  uhttps://library.ncl.res.in/content/syntheses-and-applications-c-2-symmetric-chiral-diols-001275nas a2200229   4500008004100000022001400041245009800055210006900153260010600222300001400328490000700342520039700349653000600746653001900752653003000771653002300801653003200824100001800856700002600874700002800900856011700928       2010                        eng d  a0040-403900aStereocontrolled route to the synthesis of (+/-)-3-amino-2,2-dimethyl-1,3-diphenylpropan-1-ol0 aStereocontrolled route to the synthesis of 3amino22dimethyl13dip  aTHE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLANDbPERGAMON-ELSEVIER SCIENCE LTDcNOV  a5927-59290 v513 a<p>Both the diastereomers of (+/-)-3-amino-2,2-dimethyl-1,3-diphenylpropan-1-ol were synthesized starting from a common intermediate, namely,B-hydroxy, oxime 6. Diastereoselective reduction with NaBH(4)/TiCl(4) and H(2)-Pd/C provided syn- and anti-isomers, respectively. Good overall yield and selectivity were realized using a simple protocol. (C) 2010 Elsevier Ltd. All rights reserved.</p>10a110a3-Aminoalcohol10aAldol-Tishchenko reaction10abeta-Hydroxy oxime10aDiastereoslective reduction1 aPatil, M., N.1 aBhowmick, Kartick, C.1 aJoshi, Navalkishore, N.  uhttps://library.ncl.res.in/content/stereocontrolled-route-synthesis-3-amino-22-dimethyl-13-diphenylpropan-1-ol-001566nas a2200169   4500008004100000022001400041245012800055210006900183260010600252300001400358490000700372520081800379100002201197700002201219700002601241856012901267       2014                        eng d  a0957-416600aNew organocatalyst derived from abietic acid and 4-hydroxy-L-proline for direct asymmetric aldol reactions in aqueous media0 aNew organocatalyst derived from abietic acid and 4hydroxyLprolin  aTHE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLANDbPERGAMON-ELSEVIER SCIENCE LTDcOCT  a1292-12970 v253 a<p>Enantioselective direct aldol reactions were carried out in aqueous media with a new organocatalyst that was derived from 4-hydroxy-L-proline and abietic acid via a simple and convenient synthetic protocol with a high overall yield (75%). The new organocatalyst was used for aldol reactions between substituted aromatic aldehydes and various ketones in the presence of several acid additives in aqueous media. The corresponding aldol products were obtained in high isolated yields (up to 99%) and with high anti-diastereoselectivities (up to 94%) and enantioselectivities (&gt;99.9%). The catalyst loading can be efficiently reduced to only 1 mol %. The aldol reactions were found to be extremely fast which is very unusual in organocatalyzed reactions in water. (C) 2014 Elsevier Ltd. All rights reserved.</p>1 aBhowmick, Sudipto1 aKunte, Sunita, S.1 aBhowmick, Kartick, C.  uhttps://library.ncl.res.in/content/new-organocatalyst-derived-abietic-acid-and-4-hydroxy-l-proline-direct-asymmetric-aldol-001320nas a2200169   4500008004100000022001400041245010800055210006900163260011000232300001600342490000600358520058800364100002200952700002200974700002600996856012801022       2014                        eng d  a2046-206900aSmallest organocatalyst in highly enantioselective direct aldol reaction in wet solvent-free conditions0 aSmallest organocatalyst in highly enantioselective direct aldol   aTHOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLANDbROYAL SOC CHEMISTRYcMAY  a24311-243150 v43 a<p>The catalytic efficacy of the smallest organocatalyst, L-proline hydrazide, prepared from a cheaply available natural amino acid, such as L-proline, was studied for the direct asymmetric aldol reaction of various ketones with aromatic aldehydes at room temperature in the presence of several acid additives. A loading of 10 mol% of catalyst 1 and p-toluenesulphonic acid as an additive was employed in this reaction, and good yields (up to 99%) with high anti/syn diastereoselectivities (up to 95 : 5) and enantioselectivities (up to &gt;99.9%) were achieved in aqueous media.</p>1 aBhowmick, Sudipto1 aKunte, Sunita, S.1 aBhowmick, Kartick, C.  uhttps://library.ncl.res.in/content/smallest-organocatalyst-highly-enantioselective-direct-aldol-reaction-wet-solvent-free-001672nas a2200229   4500008004100000022001400041245016200055210006900217260010300286300001000389490000700399520073200406653001901138653001801157653002501175653002601200653002001226100002201246700002201268700002601290856012601316       2015                        eng d  a0376-469900aComprehensive study on the effect of acid additives in 1(R),2(R)-Bis[(S)-prolinamido]cyclohexane catalyzed direct asymmetric aldol reactions in aqueous media0 aComprehensive study on the effect of acid additives in 1R2RBisSp  aANUSANDHAN BHAWAN, 2 RAFI MARG, NEW DELHI, 110001, INDIAbCOUNCIL SCIENTIFIC & INDUSTRIAL REScJAN  a84-920 v543 a<p>The catalytic efficacy of (1R,2R)-bis[(S)-prolinamido]cyclohexane 1, prepared from the readily available natural amino acid L-proline has been studied for the direct asymmetric aldol reaction of cyclohexanone with substituted benzaldehydes at room temperature in presence of various acid additives. A wide variety of acids e.g. aliphatic fatty acid, chiral acid, sulphonic acid, aromatic acid, etc. have been used as additive for the aldol reaction in aqueous media. A loading of 10 mol% of catalyst 1 is employed in this reaction, and good yields (up to 98% yield), diastereoselectivity (up to 96% de) and enantioselectivities (up to 87% ee) can be achieved in aqueous media within very short reaction time (1-4 hours).</p>10aacid additives10aaqueous media10aAsymmetric synthesis10adirect aldol reaction10aorganocatalysis1 aBhowmick, Sudipto1 aKunte, Sunita, S.1 aBhowmick, Kartick, C.  uhttps://library.ncl.res.in/content/comprehensive-study-effect-acid-additives-1r2r-biss-prolinamidocyclohexane-catalyzed-0