diiodomethylboronate ester, CrCl2 with TMEDA promoted borylcyclopropanation of unactivated alkenes under mild conditions. Compared with the typical Simmons–Smithcyclopropanation, the current protocol offers the following advantages: (1) the reaction proceeds stereoselectively with disubstituted alkenes even without hydroxy or alkoxy groups; (2) both electron-rich and electron-deficient alkenes can be applicable;
Enantioenriched alkylidenecyclobutanes possessing a quaternary stereogenic center, usually difficult to access, have been synthesized by combining a double boron-homologation and an allylboration through a highly efficient and diastereoselective one-pot process. Starting from commercially available substrates, this protocol represents a simple way of accessing chiral unsaturated four-membered ring
WUTS, P. G. M.;THOMPSON, P. A., J. ORGANOMETAL. CHEM., 1982, 234, N 2, 137-141
作者:WUTS, P. G. M.、THOMPSON, P. A.
DOI:——
日期:——
Borocyclopropanation of Styrenes Mediated by UV-light Under Continuous Flow Conditions
作者:Morgane Sayes、Guillaume Benoit、André B. Charette
DOI:10.1002/anie.201807347
日期:2018.10.8
Herein, we report a user‐friendly and metal‐free UV‐A light mediated borocyclopropanation of styrenes using continuousflow technology. A broad range of styrene derivatives can be cyclopropanated in good yields within 1 h residence time to produce highly valuable cyclopropylboronate esters with modest to good diastereoselectivities. The reaction is also applicable to α‐substituted styrenes. Mechanistic