Synthesis of β-Allenylamines by Addition of Chloroprene Grignards to N-Boc Imines

Abstract

The γ-selective addition of chloroprene Grignards to aromatic N-Boc aldimines enabled by 2,2′-dimorpholinodiethyl ether (DMDEE) yields the corresponding N-Boc protected β-allenylamines in good yields and regioselectivities. Transmetalation to zinc bromide also allows the addition of chloroprene Grignard to aliphatic aldimines in good yields. The obtained β-allenylamines were shown to be easily deprotected under acidic conditions and can be subjected to various transformations to access complex molecules.