Bulky Aluminum Lewis Acids as Novel Efficient and Chemoselective Catalysts for the Allylation of Aldehydes

Abstract

Bulky aluminum Lewis acids such as MAD and MABR are introduced as new efficient catalysts in substoichiometric amounts for the allylation of aldehydes with allyltributylstannane. In addition, chemoselective allylation of a less hindered or aromatic aldehyde was achieved with catalytic amounts of the carbonyl receptor aluminum tris(2,6-diphenyl-phenoxide) (ATPH).

Preparation and Addition Reactions of Allylic and Allenic Tin and Indium Reagents

“…Representative additions of allyl and methallyl tributyltin to aldehydes with the pi-ally1 platinum catalyst are summarized in Table 14. Recent work has shown that the highly hindered Lewis acid, methylaluminum bis-(4-bromo-2,6-di-tert-butylphenoxide) (MABR) catalyzes the addition of ally1 tributyltin to aldehydes in CHzClz at low temperature (Table 15) [27]. The catalyst is selec- -95 to -78 "C, 1:l syn:anti.…”