Radical
hydroalkylation of olefins enabled by hydrogen atom transfer
(HAT) catalysis represents a straightforward means to access C(sp
3)-rich molecules from abundant feedstock chemicals
without the need for prefunctionalization. While Giese-type hydroalkylation
of activated olefins initiated by HAT of hydridic carbon–hydrogen
bonds is well-precedented, hydroalkylation of unactivated olefins
in a similar fashion remains elusive, primarily owing to a lack of
general methods to overcome the inherent polarity-mismatch in this
scenario. Here, we report the use of visible-light-driven dual HAT
catalysis to achieve this goal, where catalytic amounts of an amine-borane
and an in situ generated thiol were utilized as the hydrogen atom
abstractor and donor, respectively. The reaction is completely atom-economical
and exhibits a broad scope. Experimental and computational studies
support the proposed mechanism and suggest that hydrogen-bonding between
the amine-borane and substrates is beneficial to improving the reaction
efficiency.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.