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Updated: Oct 2, 2026

Facile Preparation of (2Z,4E)-Dienamides by the Olefination of Electron-deficient Alkenes with Allyl Acetate
Published on: June 21, 2017
Difluoromethylenation of Alkynes: Streamlined Access to Allyl Difluorides
Fabien Naullet1, Sourav Mondal1, Frédéric Guégan1
1IC2MP, UMR-CNRS 7285, Université De Poitiers, Poitiers, Cedex 9, France.
Abstract:
A direct difluoromethylenation of alkynes has been developed using HF/pyridine as a dual acidic and fluorinating medium. The reaction proceeds via in situ generation of a primary oxocarbenium ion from formaldehyde, enabling efficient formation of two C(sp3)─F bonds and one C(sp2)═C(sp2) bond in a single step without the need for pre-functionalized reagents. This strategy offers a concise route to allyl difluorides as a complementary approach to incorporate difluoromethylene motifs into complex molecular frameworks. Additional spectroscopic and computational investigations provide insights into this mechanism.
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