Photoredox approach to N-Acyl-N'-aryl-N,N'-aminals using enamides and their conversion to γ-lactams
A photoredox catalytic approach to synthetically valuable N-acyl-N'-aryl-N,N'-aminals is described. This method uses the addition of a radical precursor to enamides, with subsequent interception of the cationic iminium intermediate with an arylamine. The reaction has been shown to be compatible with electron-rich and electron-deficient arylamines, and moderate to good levels of diastereoselectivity can be attained using a chiral enamide. Furthermore, the N-acyl-N'-aryl-N,N'-aminal reaction products can be readily cyclized, providing a novel synthetic route to valuable γ-lactams.
We gratefully acknowledge financial support from Loughborough University and the Tertiary Education Trust Fund (TETFund) Abuja, Nigeria (O.K.K.). We acknowledge support of the EPSRC via grant EP/M027341/1.,We gratefully acknowledge financial support from Loughborough University and the Tertiary Education Trust Fund (TETFund) Abuja, Nigeria (OKK). We thank Dr. Mark Edgar (Loughborough) for NMR structure determination; the Advanced Light Source is supported by the Director, Office of Science, Office of Basic Energy Sciences, of the U.S. Department of Energy under Contract No. DE-AC02-05CH11231; and the support of the EPSRC via grant EP/M027341/1.