Allylic functionalization of unactivated olefins with Grignard reagents.

New advances in the functionalization of unactivated olefins with carbon nucleophiles have provided more efficient and practical approaches to convert inexpensive starting materials into valuable products. Recent examples have been reported with stabilized carbon nucleophiles, tethered carbon nucleophiles, diazoesters, and trifluoromethane donors. A general method for functionalizing olefins with aromatic, aliphatic, and vinyl Grignard reagents was developed. In a one-pot process, olefins are oxidized by a commercially available reagent to allylic electrophiles, which undergo selective copper-catalyzed allylic alkylation with Grignard reagents. Products are formed in high yield and with high regioselectivity. This was utilized to synthesize a series of skipped dienes, a class of compounds that are prevalent in natural products and are difficult to synthesize by known allylic alkylation methods.