Regioselectively N-methylated azacalix[8]arene octamethyl ether prepared by catalytic aryl amination reaction using a temporal N-silylation protocol

A temporal N- silylation protocol in the catalytic aryl amination reaction has been devised to prepare nitrogen-bridged calixarene analogues. The protocol involves a smooth in situ N- silylation before aryl amination reaction, followed by spontaneous cleavage of the N-Si bond in the usual workup process, to furnish secondary aromatic amines as the cross- coupled product with no silyl group on the nitrogen atom. A successful application to the preparation of regioselectively N- methylated azacalix[ 8] arene is described, together with the crystallographic analysis.