Diphenylperhydroindolinol silyl ether

The constrained diphenylperhydroindolinol silyl ether 40 was proposed in 2009 by Lu and coworkers for the highly efficient asymmetric Michael reaction of aldehydes with nitroalkenes and gave excellent enantioselectivity (99% enantiomeric excess) in most of the cases examined (Scheme 11.42). Armstrong and coworkers studied in 2009 the use of constrained bicyclic p-proline 41 in the benchmark aldol reaction between acetone and 4-nitro-benzaldehyde, comparing it with its monocyclic analogue 42 and with (S)-proline 1 (Scheme 11.43). DFT calculations were performed to rationalise the poor selectivity of p-prolines as well as to explain the better performance of constrained p-proline 41 versus 42. ... 

Scheme 11.42 Asymmetric Michael reaction of aldehydes with nitroalkenes catalysed by diphenylperhydroindolinol silyl ether 40.

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See also in sourсe #XX -- [ ]

See also in sourсe #XX -- [ ]

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