A photocatalytic traceless C-N bond formation/cleavage strategy enabling the use of (& alpha;-chiral) alkyl aldehydes as deoxygenative (chiral) alkyl radical equivalents

A synthetic idea for the general and efficient utilization of (& alpha;-chiral) alkyl aldehydes as deoxygenative (chiral) alkyl radical equivalents based on a photocatalytic traceless C-N bond formation/cleavage strategy has been proposed and successfully applied in the alkylation/cyclization of 2-biphenylisonitriles with (& alpha;-chiral) alkyl aldehydes in the presence of amines to give a broad range of 6-alkyl-substituted phenanthridines catalyzed by 4-CzIPN under mild reaction conditions. In this transformation, & alpha;-chiral alkyl aldehydes, e.g. chiral & alpha;-amino aldehydes, have been used for the first time as deoxygenative chiral alkyl radical equivalents, without erosion of the optical purity of the chiral centers inherited from the corresponding mother aldehyde, in most cases.