Jorgensen-Hayashi catalyst, addition with

Jorgensen and co-workers reported the enantioselective a-sulfenylation of aldehydes catalyzed by 6b (Equation 10.16) [34]. Hayashi et al. reported the 1,4-addition reaction of acetaldehyde with nitrostyrene in the presence of 6a (Scheme 10.17) [35]. The introduction of a siloxy group into proline increased its catalytic activity, thus allowing for a decrease in catalyst load and reaction time without compromising the... 

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