A Domino Sequence Consisting of Insertion, Coupling, Isomerization, and Diels–Alder Steps Yields Highly Fluorescent Spirocycles

Abstract

Four bonds at one stroke and products with intensive fluorescence result from a domino sequence consisting of insertion, coupling, isomerization, and Diels–Alder steps (see scheme, Ts=tosyl). Alkynoyl ortho-iodophenyl esters or N-(iodophenyl)alkynanilides 1 react with propargyl allyl ethers 2 to furnish spirocycles 3.