A selective one-pot procedure was developed for the production of E-dihalo-substituted α,β-unsaturated alkenoic acids and derivatives from the corresponding α,β-unsaturated alkynoic acids.
Facile Synthesis of <i>E</i>‐Diiodoalkenes: H<sub>2</sub>O<sub>2</sub>‐Activated Reaction of Alkynes with Iodine
作者:Alexander O. Terent'ev、Dmitry A. Borisov、Igor B. Krylov、Gennady I. Nikishin
DOI:10.1080/00397910701545171
日期:2007.9.1
activate iodine in the addition reaction with triple bonds. A facile and technologically straightforward procedure was developed for the synthesis of E‐diiodoalkenes based on the reaction of alkynes with an I2–H2O2 system in THF. Selective iodination of terminal and internal alkynes containing electron‐donating and electron‐withdrawing substituents afforded 16 E‐diiodoalkenes in yields up to 89%.
Carboxylate-Directed Tandem Functionalisations of α,β-Dihaloalkenoic Acids with 1-Alkynes: A Straightforward Access to (Z)-Configured, α,β-Substituted γ-Alkylidenebutenolides
and stereoselectively leads to rarely described (Z)‐3‐halo‐5‐ylidene‐5H‐furan‐2‐ones. These compounds are subsequently able to undergo classical Pd‐catalysed cross‐coupling reactions, providing 3‐substituted and 3,4‐disubstituted 5‐ylidene‐5H‐furan‐2‐ones (see scheme).