A facile method has been developed for the synthesis of chiral piperazines through Ir-catalyzed hydrogenation of pyrazines activated by alkyl halides, giving a wide range of chiral piperazines including 3-substituted as well as 2,3- and 3,5-disubstituted ones with up to 96% ee. The high enantioselectivity, easy scalability, and concise drug synthesis demonstrate the practical utility.
Inherent vs Apparent Chemoselectivity in the Kumada–Corriu Cross-Coupling Reaction
作者:XiYe Hua、Jeanne Masson-Makdissi、Ryan J. Sullivan、Stephen G. Newman
DOI:10.1021/acs.orglett.6b02631
日期:2016.10.21
The Kumada–Corriu reaction is a powerful tool for C–C bond formation, but is seldom utilized due to perceived chemoselectivity issues. Herein, we demonstrate that high-yielding couplings can occur in the presence of many electrophilic and heterocyclic functional groups. Our strategy is mechanically based, matching oxidative addition rates with the rate of syringe pump addition of the Grignard reagent
COMPOUNDS AND METHODS FOR ANALYSIS AND SYNTHESIS OF SACCHARIDE COMPOUNDS
申请人:ACADEMIA SINICA
公开号:US20150168415A1
公开(公告)日:2015-06-18
Provided is an isotope-labelled compound having a general formula IIa′, S-Y′-BIM, wherein S is a sugar moiety, Y′ is an isotope-containing sensor moiety and BIM is a benzimidazole. The compound may be used as an agent for saccharide analysis by magnetic resonance spectroscopy (NMR). A new glycan sequencing method and a glycoprotein synthesis method by using these compounds are also provided.
Transition-metal-free coupling of haloarenes with unactivated arenes has been developed in the presence of NaH and 1,10-phenanthroline. Various haloarenes bearing methyl, methoxy, halogen (fluoride, chloride, and bromide), cyano, trifluoromethyl, ester, and amide groups can be cross-coupled with unactivated arenes, or heteroarenes in this reaction.