Mn-Catalyzed Electrochemical Chloroalkylation of Alkenes

The
heterodifunctionalization of alkenes is an efficient method
for synthesizing highly functionalized organic molecules. In this
report, we describe the use of anodically coupled electrolysis for
the catalytic chloroalkylation of alkenesa reaction that constructs
vicinal C–C and C–Cl bonds in a single synthetic operationfrom
malononitriles or cyanoacetates and NaCl. Knowledge of the persistent
radical effect guided the reaction design and development. A series
of controlled experiments, including divided-cell electrolysis that
compartmentalized the anodic and cathodic events, allowed us to identify
the key radical intermediates and the pathway to their electrocatalytic
formation. Cyclic voltammetry data further support the proposed mechanism
entailing the parallel, Mn-mediated generation of two radical intermediates
in an anodically coupled electrolysis followed by their selective
addition to the alkene.