TY - JOUR T1 - Asymmetric Michael addition of ketones to nitroolefins: pyrrolidinyl-oxazole-carboxamides as new efficient organocatalysts. AU - Kamal,Ahmed, AU - Sathish,Manda, AU - Srinivasulu,Vunnam, AU - Chetna,Jadala, AU - Chandra Shekar,Kunta, AU - Nekkanti,Shalini, AU - Tangella,Yellaiah, AU - Shankaraiah,Nagula, PY - 2014/9/3/entrez PY - 2014/9/3/pubmed PY - 2015/6/3/medline SP - 8008 EP - 18 JF - Organic & biomolecular chemistry JO - Org Biomol Chem VL - 12 IS - 40 N2 - Chiral pyrrolidinyl-oxazole-carboxamides were synthesized and used as efficient new organocatalysts for the asymmetric Michael addition of ketones with nitroalkenes under solvent-free conditions. Gratifyingly, the corresponding Michael adducts were obtained in higher yields (up to 99%) and excellent stereoselectivities (up to >99/1 dr and 99% ee). Transition state models have been proposed to account for the high enantio- and diastereoselectivity of these Michael addition reactions and also the energetics have been investigated using density functional methods. These results support the preferential formation of syn-products by the approach of trans-β-nitrostyrene through the re-face of anti-enamine. SN - 1477-0539 UR - https://www.unboundmedicine.com/medline/citation/25181422/Asymmetric_Michael_addition_of_ketones_to_nitroolefins:_pyrrolidinyl_oxazole_carboxamides_as_new_efficient_organocatalysts_ DB - PRIME DP - Unbound Medicine ER -