Abstract
An innovative visible-light-driven direct hydrogen atom transfer (
d-HAT) of Ge–H bond has been developed, wherein the photoexcited
9,10-phenanthraquinone ( PCHAT9) serves as an
efficient photocatalyst for the generation of germanium-centered
radicals from triphenylgermane. By employing hypervalent iodine reagents
as SOMOphiles, this protocol facilitates streamlined germylation through
a mechanism involving germyl radical addition followed by β-cleavage of
a carboxyl radical to yield a diverse array of ethynyl-, vinyl-,
nitrile-, and phenyl-functionalized germanes. The methodological leap
signifies a noteworthy departure from the previous photocatalytic
indirect hydrogen atom transfer ( i-HAT) relying on combined
usage of PC SET with abstractors, which not only
advances the methodology for creating germanium radicals in a
photocatalytic fashion but also provides access to structurally novel
and pharmaceutically promising organogermanium compounds that are
difficult to synthesize by routine methods.