A highly efficient and stereoselective method for the synthesis of (1Z)‐1,2‐dihalo‐3‐vinyl‐1,3‐dienes featuring palladium‐catalyzed coupling of haloalkynes and 2,3‐butadienyl acetates was developed. The resulting products were smoothly converted into cis‐1,2‐dihalostyrene derivatives using the Diels–Alder/aromatization sequence.
Pd-catalyzed coupling of haloalkynes with allyl acetate has been reported, providing a convenient method for the stereoselective synthesis of (Z)-β-haloenol acetates in good yields. The synthetic utility of this method is demonstrated by the formation of functionalized enol acetates via the Suzuki–Miyaura or Sonogashira coupling of the resulting (Z)-β-haloenol acetate products.
Diethyl 1,1-dichloromethylphosphonate (2) was synthesised in good yield from the reduction of 1,1,1-trichloromethylphosphonate (1) with i-C3H7MgCl and subsequent hydrolysis. The reactivity of 2 towards α-alkylation and its utility in the synthesis of chloroalkynes and terminal alkynes was investigated.