Synthesis of Terminal 1,3-Diynes via Sonogashira Coupling of Vinylidene Chloride Followed by Elimination. Preparation of 1,3-Decadiyne

A Celebration of the Publication of the 100th Volume of Organic Syntheses

“…To demonstrate the nuances learned during the development and checking of procedures for reproducibility, Danheiser cited his own lab’s work to prepare 1,3-diynes, where internal temperature control (below −70 °C) during the addition of chloroenyne to lithium diisopropylamide (LDA) was determined to be critical to a successful transformation with only trace amounts of an allene-yne side product (Scheme A) . In another example, the Takai–Lombardo alkylidenation to prepare ( Z )-alkenyl ethers did not proceed in the Boeckman laboratory when using high-purity zinc available but instead required the presence of traces of lead (0.04–0.07 mol %) in the zinc powder to be effectivewhich led to the modern-day protocol using a catalytic amount of lead chloride (Scheme B). − …”