Diastereofacial Selectivity in the Reaction of Allylic Organometallic Compounds with Imines. Stereoelectronic Effect of Imine Group

Article abstract of DOI:10.1021/jo00217a020

The diastereofacial selectivity in the reaction of crotyl organometallic compounds (4) (M = Li⁺, Mg, B, and Sn) with imines (3) is investigated.The reaction of ordinary imines produces the erythro isomer (5) predominantly regardless of the metal (M).With increase of the steric bulk of the R group or with aryl substituent in the R' group, the threo isomer (6) predominates in the reaction of crotyl-9-BBN.The ratio of erythro (11)/threo (12) in the reaction of pent-3-en-2-yl-9-BBN (9) is higher then the ratio of erythro (5)/threo (6) in the reaction of crotyl-9-BBN itself.On the basis of these observations, the transition-state geometry is discussed.