Harnessing Additional Capability from in Water Reaction Conditions: Aldol<i>versus</i>Knoevenagel Chemoselectivity
作者:Thomas C. Nugent、Falguni Goswami、Samarpita Debnath、Ishtiaq Hussain、Hussein Ali El Damrany Hussein、Alka Karn、Srinuvasu Nakka
DOI:10.1002/adsc.202100301
日期:2021.7.20
racemic or enantioselective, has not been previously demonstrated in the presence of Knoevenagel active functional groups. Here, we show that unhindered β-diketones remain unreacted while a ketone moiety undergoes a highly enantioselective aldol desymmetrization resulting in three new stereogenic centers using in water reaction conditions. A mechanistic hypothesis for the chemoselective formation of either
Advances towards Highly Active and Stereoselective Simple and Cheap Proline-Based Organocatalysts
作者:Francesco Giacalone、Michelangelo Gruttadauria、Paola Agrigento、Paolo Lo Meo、Renato Noto
DOI:10.1002/ejoc.201000913
日期:2010.10
at loadings of 2–0.1 mol-% for the direct asymmetric aldolreaction in water by using variable amounts of water. Among them, a new catalyst, the L-proline carrying a trans-4-(2,2-diphenylacetoxy) group, and a catalyst previously synthesized by us, the L-proline carrying a trans-4-(4-phenylbutanoyloxy) group, were found to be excellent catalysts for the aldolreaction between cyclohexanone or cyclopentanone