1,2-H Shift in Copper−Chlorocarbenoid Intermediate during CuCl/bpy-Promoted Stereoselective Dechlorination of 2,2,2-Trichloroethyl Alkyl Ethers to (Z)-1-Alkoxy-2-chloroethenes

Abstract

Reaction of 2,2,2-trichloroethyl alkyl ethers with 2 molar equiv of CuCl/bpy in refluxing DCE yielded (Z)-1-alkoxy-2-chloroethenes stereoselectively as the major product via 1,2-H shift in copper-chlorocarbenoid intermediate. 2,2,2-Trichloroethyl carboxylates undergo a radical 1,2-acyloxy shift under similar conditions.

New method of preparation of alkoxyacetic acids

“…After evaporation, ether Ib produced 1.64 g of a mix ture of compounds IIb and IVb in 25 : 75 ratio (accord ing to GLC and NMR data), column chromatography IR and 13 C NMR spectra were the most informa tive methods to establish the structure of the obtained compounds (IIa, IIb-IVa, IVb) isolated by column chromatography ( Table 2). The obtained spectral and physicochemical characteristics of esters IIa, IIb and aldehydes IIIa, IIIb agree well with the literature data [5][6][7][8][9].…”

Copper(I)‐Promoted Synthesis of Highly Substituted and Functionalized Tetrahydrothiophenes

“…An interesting dechlorinative rearrangement occurred to give 3‐acetoxydihydrothiophene 9 in 56 % yield. A mechanism involving a Zn‐carbenoid species has been proposed for the formation of 9 .…”

Au‐Catalyzed Addition of Nucleophiles to Chloroalkynes: A Regio‐ and Stereoselective Synthesis of (Z)‐Alkenyl Chlorides

“…Recently, Dérien and co‐workers reported a Ru‐catalyzed addition of HCl to alkynes for the substituted alkenyl chlorides (Scheme a) . Ram's group discovered an efficient method for the synthesis of 2‐chloroalkeneyl ethers via CuCl/bpy‐promoted stereoselective dechlorination of 2,2,2‐Trichloroethyl Alkyl Ethers (Scheme b) . Hultin's group reported a useful method for the formation of ( Z )‐2‐chloroalkenyl ethers via palladium‐catalyzed cross coupling of ( E )‐1,2‐dichlorovinyl ethers with aryl boronic acid (Scheme c) .…”