Azidophosphonium salt-directed chemoselective synthesis of ( E )/( Z )-cinnamyl-1 H -triazoles and regiospecific access to bromomethylcoumarins from Morita-Baylis-Hillman adducts.

The direct transformation of Morita-Baylis-Hillman (MBH) adducts into molecules of interest is a crucial process wherein allylic hydroxy-protected or halogenated MBH adducts are commonly preferred. Herein, we report an azidophosphonium salt (AzPS)-catalysed straight forward protocol for synthesising structurally demanding ( E )/( Z )-cinnamyl-1 H -1,2,3-triazoles and halomethylcoumarins from MBH adducts. The novel methodology, efficient catalyst, and direct utilization of MBH adducts under mild reaction conditions qualify the reported procedures as powerful synthetic tools.
(Copyright © 2020, Karthikeyan et al.; licensee Beilstein-Institut.)