Reactivity control in the addition of N,N′-dialkylated 1,n-diamines to activated skipped diynes: Synthesis of fused bicyclic 1,4-diazepanes and 1,5-diazocanes

摘要

A metal-free domino reaction for the synthesis of a new family of fused bicyclic 1,4-diazepanes and 1,5-diazocanes has been developed. The reaction involves the use of N,N′-dialkylated 1,n-diamines as the nitrogen source, through-space orbital interactions between the two nitrogen atoms as the reactivity director element, and an activated skipped diyne as the reactive platform. A key Morita-Baylis-Hillman-like reaction allows the formation of 1,4-diazepanes and 1,5-diazocanes (medium-sized diazoheterocycles). These structures incorporate a 1,n-diazocycle fused to a Î3-butenolide ring and different functionalities to be used as convenient handles for further complexity generation. The good efficiency of this reaction and its simple experimental protocol make this process an excellent candidate for the fast construction of structure-focused libraries based on this fused bicyclic motif. © 2011 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.