Michael benzamides

A short and efficient syntl thiazoline-5-carboxylates 143 and benzamides as well as developed (Scheme 46) [53, Michael addition of 142-X acr conditions followed by an in chlorine substituent. Cl + C02Me 1-Me, 2-Me lesis of 4-spirocyclopropane-annt and 144 from chlorocyclopropylid benzthioamides 142-X, respecti 72, 87]. This domino transforma OSS the double bond of 1-Me or 2-tramolecular nucleophilic substiti NaH, DMF. X Reaction dated oxa- and eneacetates 1,2 vely, has been tion involves a Me under basic Lition of the a- C02Me 143, 144 ... 

Glutamine-Glycine Cleavage Site 3-Carbamoyl-benzaldehyde Michael acceptor benzamide Fig. 12.24 Cinnamic derivatives as vinylogues of benzaldehyde. ... 

As shown in Eq. (7.73), alkenylation reactions with benzamide as the substrate give ortto-alkenylation derivatives as the cyclometalation derivatives. However, an alkenylation product can undergo a further Michael reaction to give a y-lactam in the case of electron-withdrawing alkenes in a high yield, as shown in Eq. (7.79) [154,155]. 

The same reaction in water applied to A -pentafluorophenyl benzamides led to the mono aUcenylation of benzamides followed by intramolecular aza-Michael addition and formation of lactams [(Eq. 66)] [147]. 

Tian and Lin disclosed a Rh(III)-catalyzed arylative cyclization reaction of 1,6-enynes with JV-(pivaloyloxy)benzamides for the synthesis of a new type of tetracyclic isoquinolones 76 in quantitative yields [39]. Product formation fully depends on the O-substituted JV-hydroxybenzamide substrate. For example, treatment of A/ -(pivaloyloxy)benzamide with 1,6-enynes in the presence of acetone afforded polycycUc products 76 by a Michael addition process (Eq. (5.74)), whereas the treatment of A/ -(methoxy)benzamide did not afford the Michael addition product. 

They subsequently found that N-alkenoyl-2-methoxybenzamide was the best substrate among the corresponding benzamides [87]. Several active methylene compounds could be employed as nucleophiles to give the Michael adducts in good to excellent yields with up to 93% ee (Scheme 2.36). 

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