Grignard reagents Michael addition

This Michael-type addition is catalyzed by lanthanum(3+) [16096-89-2] (80). Ethylene glycol [107-21-1] reacts with maleate under similar conditions (81). A wide range of nucleophilic reagents add to the maleate and fumarate frameworks including alcohols, ammonia, amines, sulfinic acids, thioureas, Grignard reagents, Michael reagents, and alkali cyanides (25). 

Few a-ketosulphoxides 123 were prepared by trapping the enolate anions 124, which are generated by the Michael addition of Grignard reagents to easily available a, jS-unsaturated carbonyl compounds 125, with methanesulphinyl chloride174 (equation 65). 

An arenethiolatocopper (I) complex has been used by van Koten et al. to catalyse the 1,4-Michael addition of Grignard reagents to acyclic enones, providing the corresponding products with excellent chemoselectivities, high... 

Scheme 2.11. Michael additions of functionalized organocopper reagents derived from Grignard compounds.

The Michael additions of various carbon nucleophiles such as cyanide [15b, 22b], anions generated from nitromethane [27], ferf-butyl acetate [9], malon-ates [27] and O Donnell s glycine equivalent [541, cuprates [9,15b] or Grignard reagents [53] under copper catalysis [55] have also been reported (Scheme 24). 

A stereocontrolled synthesis of racemic monomorine I (16a) has been accomplished by Stevens and Lee (438). An allyl alcohol obtained by reaction of acrolein with the Grignard reagent of the chloroacetal (367) was oxidized to yield the enone (368). The Michael addition of 1-nitropentane to 368 was catalyzed by tetramethylguanidine to yield the nitroalkane (369). Reductive cyclization of 369... 

Mukaiyama et al. 200) synthesized optically active 3-substituted succinialdehyde acid esters (204) via a Michael-addition. The methyl ester of fumaraldehydic acid was converted into the corresponding aminal (203) by treatment with the (S)-proline-derived chiral diamine (99). The Michael-addition of Grignard reagent to the aminal, followed by hydrolysis produced stereoselectivily 3-substituted succinaldehydic acid ester (204) in good yield. 

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