The solid copper-mediated C-N cross-coupling of phenylboronic acids under continuous flow conditions

We have developed two general methods for the C-N cross-coupling of phenylboronic acids with amines using solid copper flow reactors, in combination with an oxidant. We have developed one method for a C-N arylation reaction which employs a solid copper coil reactor, in combination with tert-butyl peroxybenzoate, to give products in moderate isolated yields. We have also developed a general method for the C-N cross coupling of phenylboronic acids using a column packed with solid copper powder, in combination with acetic acid and TEMPO, to give products in isolated yields in excess of 75+%. We have also applied our general copper powder method to generate a library of products which highlights the utility of solid copper flow reactors for C-N cross coupling reactions, generating 16 examples in good yields. Mechanistic implications and future directions are also discussed. (C) 2016 Elsevier Ltd. All rights reserved.