posted on 2021-01-19, 22:43authored byGaoyuan Zhao, Wang Yao, Jaclyn N. Mauro, Ming-Yu Ngai
Excited-state catalysis, a process
that involves one or more excited
catalytic species, has emerged as a powerful tool in organic synthesis
because it allows access to the excited-state reaction landscape for
the discovery of novel chemical reactivity. Herein, we report the
first excited-state palladium-catalyzed 1,2-spin-center shift reaction
that enables site-selective functionalization of carbohydrates. The
strategy features mild reaction conditions with high levels of regio-
and stereoselectivity that tolerate a wide range of functional groups
and complex molecular architectures. Mechanistic studies suggest a
radical mechanism involving the formation of hybrid palladium species
that undergoes a 1,2-spin-center shift followed by the reduction,
deuteration, and iodination to afford functionalized 2-deoxy sugars.
The new reactivity will provide a general approach for the rapid generation
of natural and unnatural carbohydrates.