Reaction conditions allowing a stereoretentive cross-coupling of alkenyl sulfides with Grignardreagents using ligand-free Pd catalysis are discussed here. The presence of an adequately positioned OH function is a key feature that allows a Mg-promoted Lewis acid activation of the mercaptide leaving group. This easy to implement procedure actually relies on an in situ generation of stable Pd nanoparticles
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