01672nas 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