Nickel-Catalyzed 1,2-Carboamination of Alkenyl Alcohols

An alcohol-directed, nickel-catalyzed
three-component umpolung
carboamination of unactivated alkenes with aryl/alkenylboronic esters
and electrophilic aminating reagents is reported. This transformation
is enabled by specifically tailored O-(2,6-dimethoxybenzoyl)­hydroxylamine
electrophiles that suppress competitive processes, including undesired
β-hydride elimination and transesterification between the alcohol
substrate and electrophile. The reaction delivers the desired 1,2-carboaminated
products with generally high regio- and syn-diastereoselectivity
and exhibits a broad scope of coupling partners and alkenes, including
complex natural products. Various mechanistic experiments and analysis
of the stereochemical outcome with a cyclic alkene substrate, as confirmed
by X-ray crystallographic analysis, support alcohol-directed syn-insertion of an organonickel­(I) species.