One-pot synthesis of (Z)-β-sulfonyl enoates from ethyl propiolate
作者:C. Wade Downey、Smaranda Craciun、Ana M. Neferu、Christina A. Vivelo、Carly J. Mueller、Brian C. Southall、Stephanie Corsi、Eric W. Etchill、Ryan J. Sault
DOI:10.1016/j.tetlet.2012.08.051
日期:2012.10
β-Sulfonyl enoates may be synthesized through a one-pot two-step sequence from ethylpropiolate with good to excellent selectivity for the Z isomer. Trialkylamines catalyze thioconjugate additions of aryl thiols, and alkoxides catalyze the addition of aliphatic thiols. Addition of meta-chloroperbenzoic acid (mCPBA) and LiClO4 to the reaction mixture provides rapid access to the sulfonyl enoates. Yields
Triphenylphosphine-Catalyzed Stereoselective Synthesis of Alkyl 3-(2-Naphthylsulfanyl)-2-propenoate from Alkyl Acetylenecarboxylates and 2-Naphthalenethiol
作者:Ali Ramazani、Sadegh Salmanpour、Issa Amini
DOI:10.1080/10426500802266126
日期:2009.3.10
Protonation of the highly reactive 1:1 intermediates, produced in the reaction between triphenylphosphine and alkyl acetylenecarboxylates by 2-naphthalenethiol, leads to vinyltriphenylphosphonium salts, which undergo an addition-elimination reaction to produce the corresponding S-vinyl thioethers. The NMR spectra indicated that the compounds contained two stereoisomers for each S-vinyl thioether; their ratio was determined on the basis of 1H NMR spectra. The reaction is fairly stereoselective.