Department of Chemistry, University of California, Irvine, Irvine, California 92697, United States.
J Am Chem Soc. 2021 Apr 28;143(16):6176-6184. doi: 10.1021/jacs.1c00939. Epub 2021 Apr 15.
In this article, we advance Rh-catalyzed hydrothiolation through the divergent reactivity of cyclopropenes. Cyclopropenes undergo hydrothiolation to provide cyclopropyl sulfides or allylic sulfides. The choice of bisphosphine ligand dictates whether the pathway involves ring-retention or ring-opening. Mechanistic studies reveal the origin for this switchable selectivity. Our results suggest the two pathways share a common cyclopropyl-Rh(III) intermediate. Electron-rich Josiphos ligands promote direct reductive elimination from this intermediate to afford cyclopropyl sulfides in high enantio- and diastereoselectivities. Alternatively, atropisomeric ligands (such as DTBM-BINAP) enable ring-opening from the cyclopropyl-Rh(III) intermediate to generate allylic sulfides with high enantio- and regiocontrol.
在本文中，我们通过环丙烯的不同反应性来推进 Rh 催化的氢硫加成反应。环丙烯可以进行氢硫加成反应，生成环丙基硫醚或烯丙基硫醚。双膦配体的选择决定了反应途径是涉及环保持还是开环。机理研究揭示了这种可切换选择性的起源。我们的结果表明这两种途径共享一个共同的环丙基-Rh(III)中间体。富电子的 Josiphos 配体促进从该中间体的直接还原消除，以高对映选择性和非对映选择性提供环丙基硫醚。或者，轴手性配体（如 DTBM-BINAP）可以使环丙基-Rh(III)中间体开环，以高对映选择性和区域选择性生成烯丙基硫醚。
