Palladium-catalyzed alkenyl epoxide

Alkenyl substituents attached to aziridine ring carbons allow a palladium-catalyzed carbonyl-insertion reaction to occur, producing a /1-lactam (Scheme 46) <91SL91>. The proposed mechanism <93BMC2415> is based on an analogous reaction of vinyl epoxides <85JA6123>. Initial attack of palladium(O) on the optically active /ra .s-vinylaziridine (67) leads to the zr-allyl palladium complex... 

The comparison of intramolecular carbopalladation reactions of allenes and alkenes outlined in Schemes 9-5 and 9-6 illustrates that not every transition metal catalyzed ring closure necessarily involves a template effect. Others, however, clearly benefit from it. A prototype example is the palladium catalyzed cycloisomerization of alkenyl epoxides carrying distal pre-nucleophiles [38, 39], representing one variant of the famous Tsuji-Trost allylation [40]. 

V.2.1.5 Palladium-Catalyzed Substitution Reactions of Alkenyl Epoxides... 

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