Asymmetric Remote Addition Reactions of Heterocycle-Based Dearomative Dienamine or Trienamine Species to 1-Azadienes: Application to Construct Chiral Azocanes and Azecanes

The dearomative dienamines between a few five-membered heteroaryl aldehydes and chiral secondary amine catalysts underwent highly regio-, chemo- and stereoselective Michael additions to 1-azadienes derived from 2-methylenebenzofuran-3(2H)-ones or 2-methylenebenzo[b]thiophen-3(2H)-ones. The very remote epsilon-regioselective Michael-type additions could be similarly realized by employing the analogous dearomative trienamine species from beta-indolyl unsaturated aldehydes. The resulting multifunctional products enabled the efficient construction of enantioenriched chiral azocane or even azecane frameworks with high molecular complexity.