Emergent Strategies for Catalytic Enantioselective Direct Thiocyanation and Selenocyanation Reactions

[摘要] Organothiocyanates and selenocyanates stood out overthe last two decades as high-profile targets in synthetic organic chemistry. These classes of molecules, which havebeen known since the 1930s, have been the object of a recent revival of interest, especially regarding their synthesis.1 The SCN and SeCN moieties are indeed of notable importance. In addition to be found in several bioactive natural products, which exhibit interesting anticancer andantibacterial activities for most of them, they are importantsynthetic linchpin to access other biorelevant sulfur- andselenium-containing functional groups. In this context, andeven though the formation of C(sp3)–SCN and C(sp3)–SeCNbonds has been well documented, a simple observationstrikes: enantioselective thiocyanation and selenocyanationreactions, i.e., the direct introduction of the SCN or SeCNmoieties on a carbon center in an enantioselective fashion,have long remained a challenge to be overcome. Several examples have been reported to access chiral organic thiocyanates for natural products synthesis endeavors, via SN2 nucleophilic substitutions with SCN nucleophiles on alreadychiral nonracemic substrates.2 Along with these developments, an early report from Falck and co-workers describesthe diastereoselective -thiocyanation of chiral N-acyl oxazolidinones using Evan’s protocol.

[学科分类] 精神健康和精神病学

[关键词] thiocyanates;selenocyanates;asymmetric synthesis;enantioselectivity;organocatalysis;Lewis acid catalysis