Combining the catalytic enantioselective reaction of visible-light-generated radicals with a by-product utilization system

We report an unusual reaction design in which a chiral bis-cyclometalated rhodium(III) complex enables the stereocontrolled chemistry of photo-generated carbon-centered radicals and at the same time catalyzes an enantioselective sulfonyl radical addition to an alkene. Specifically, employing inexpen...

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Bibliographic Details
Main Authors: Huang, Xiaoqiang, Luo, Shipeng, Burghaus, Olaf, Webster, Richard David, Harms, Klaus, Meggers, Eric
Other Authors: School of Physical and Mathematical Sciences
Format: Journal Article
Language:English
Published: 2017
Subjects:
Online Access:https://hdl.handle.net/10356/86888
http://hdl.handle.net/10220/44207
Description
Summary:We report an unusual reaction design in which a chiral bis-cyclometalated rhodium(III) complex enables the stereocontrolled chemistry of photo-generated carbon-centered radicals and at the same time catalyzes an enantioselective sulfonyl radical addition to an alkene. Specifically, employing inexpensive and readily available Hantzsch esters as the photoredox mediator, Rh-coordinated prochiral radicals generated by a selective photoinduced single electron reduction are trapped by allyl sulfones in a highly stereocontrolled fashion, providing radical allylation products with up to 97% ee. The hereby formed fragmented sulfonyl radicals are utilized via an enantioselective radical addition to form chiral sulfones, which minimizes waste generation.