Photocatalytic C−C Bond Cleavage and Amination of Cycloalkanols by Cerium(III) Chloride Complex

Abstract

A general strategy for the cleavage and amination of C-C bonds of cycloalkanols has been achieved through visible-light-induced photoredox catalysis utilizing a cerium(III) chloride complex. This operationally simple methodology has been successfully applied to a wide array of unstrained cyclic alcohols, and represents the first example of catalytic C-C bond cleavage and functionalization of unstrained secondary cycloalkanols.

Visible‐Light‐Promoted Ring‐Opening Alkynylation, Alkenylation, and Allylation of Cyclic Hemiacetals through β‐Scission of Alkoxy Radicals

“…Since the alkoxy radicals originated from unstrained cycloalkanols are known to undergo ring‐opening through β‐scission of the C−C bonds, we have attempted to expand the transformation to N ‐alkoxyphthalimides 8 and 9 . Comparison of the reduction potential of the compounds 1 a , 8 , and 9 suggests that 8 and 9 may also be reduced under the standard conditions via the SET process (Scheme ) .…”

Radical‐Promoted C−C Bond Cleavage: A Deconstructive Approach for Selective Functionalization

“…Seeking to overcome some of the limitations, Zuo and co‐workers reported a strategy for the fragmentation of unstrained cycloalkanols, including secondary alcohols . The key point in this strategy lies in the use of a cerium(III) chloride complex as a photoredox catalyst, which behaves as an efficient ligand‐to‐metal charge transfer (LMCT) .…”

Radical‐Promoted C−C Bond Cleavage: A Deconstructive Approach for Selective Functionalization

“…[32] Thek ey to this elegant solution relies on the formation of the arene radical cation N,w hich serves as internal oxidant of ap roximal O À Hb ond. [34] The key point in this strategy lies in the use of ac erium(III) chloride complex as aphotoredox catalyst, which behaves as an efficient ligand-to-metal charge transfer (LMCT). Under these reaction conditions,t he ring-strain energy is not ap rerequisite to furnishing an efficient b-fragmentation that leads to fragmentation of several ring sizes.The synthetic utility of this strategy is clear since the deconstruction/hydrogenation of complex natural product derivatives such as the hecogenin analogue 15 a,can be attained.…”