Rhenium-Catalyzed Regio- and Stereoselective Addition of Imines to Terminal Alkynes Leading to N-Alkylideneallylamines
摘要:
The reaction of terminal allcynes with imines using ReBr(CO)(5) as a catalyst results in the production of N-alkylideneallylamines and not the conventional propargylamines. The substituent on the imine nitrogen is important, and a diphenylmethyl group gave the best result. The catalytic cycle of this regio selective C-C bond forming reaction appears to involve the formation of an alkynyl rhenium species and subsequent nucleophilic attack of the alkynyl beta-carbon atom on the imine carbon to give a vinylidene rhenium species.
Self-assembled organic–inorganic hybrid silica with ionic liquid framework: a novel support for the catalytic enantioselective Strecker reaction of imines using Yb(OTf)3–pybox catalyst
作者:Babak Karimi、Aziz Maleki、Dawood Elhamifar、James H. Clark、Andrew J. Hunt
DOI:10.1039/c0cc01426e
日期:——
Yb(OTf)3âpybox is immobilized in a novel self-assembled ionic liquid hybrid silica and has been successfully applied as a catalyst for the asymmetric Strecker hydrocyanation of aldimines. This catalytic system can be reused for at least 6 times without any significant loss of activity and enantioselectivity.
2-methyl-2-propanethiolate and ketenes, react with imines in the presence of stannous triflate to give the corresponding β-aminocarboxylic thioesters in an anti-selective manner. This method is successfully applied to a diastereoselective synthesis of a carbapenem antibiotic PS-5 intermediate.
锡 (II) 羧酸硫酯烯醇化物由 2-甲基-2-丙硫醇亚锡和烯酮原位形成,在三氟甲磺酸亚锡存在下与亚胺反应,以抗选择性方式生成相应的 β-氨基羧酸硫酯。该方法成功应用于碳青霉烯类抗生素PS-5中间体的非对映选择性合成。
Oxazoline-Based Organocatalyst for Enantioselective Strecker Reactions: A Protocol for the Synthesis of Levamisole
作者:Arghya Sadhukhan、Debashis Sahu、Bishwajit Ganguly、Noor-ul H. Khan、Rukhsana I. Kureshy、Sayed H. R. Abdi、E. Suresh、Hari C. Bajaj
DOI:10.1002/chem.201302007
日期:2013.10.11
catalyze asymmetric Streckerreactions of various aromatic and aliphatic N‐benzhydrylimines with trimethylsilylcyanide (TMSCN) as a cyanide source at −20 °C to give α‐aminonitriles in high yield (96 %) with excellent chiral induction (up to 98 % ee). DFT calculations have been performed to rationalize the enantioselective formation of the product with the organocatalyst in these reactions. The organocatalyst