An efficient RhII -catalyzed synthesis of functionalized α-vinyl aldehydes with high E/Z stereoselectivity was developed. The reaction mediates the cyclopropanation of enaminones with vinyl carbenoids that are generated from cyclopropenes in situ to give the aminocyclopropane intermediates. Selective C-C bond cleavage of the cyclopropane intermediates leads to formation of α-vinyl aldehyde derivatives
We report realization of the first enantioselective Cope-type hydroamination of oximes for asymmetric nitrone synthesis. The ligand promoted asymmetriccyclopropene “hydronitronylation” process employs a Cu-based catalytic system and readily available starting materials, operates under mild conditions and displays broad scope and exceptionally high enantio- and diastereocontrol. Preliminary mechanistic
structures are important components of biologically active natural products and pharmaceuticals. We herein report the enantioselective intermolecularhydroamination of substituted cyclopropenes with various amines catalyzed by chiral half‐sandwich rare‐earth‐metal complexes. This method constitutes a 100 % atom‐efficient route for the synthesis of a variety of chiral α‐aminocyclopropane derivatives in high
Asymmetric Copper-Catalyzed Carbomagnesiation of Cyclopropenes
作者:Longyang Dian、Daniel S. Müller、Ilan Marek
DOI:10.1002/anie.201701094
日期:2017.6.6
polysubstituted cyclopropanes was easily achieved through the asymmetric copper‐catalyzed carbomagnesiation reaction of nonfunctionalized cyclopropene derivatives. The carbometalated species generated in situ readily undergo C−C and C−X bond‐forming reactions with various electrophiles with complete retention of configuration.
An enantioselective C−H addition to a C=C bond represents the most atom‐efficient route for the construction of chiral carbon–carbon skeletons, a central research topic in organic synthesis. We herein report the enantioselective yttrium‐catalyzed C(sp3)−H bond addition of 2‐methyl azaarenes, such as 2‐methyl pyridines, to various substituted cyclopropenes and norbornenes. This process efficiently afforded
C = C键上的对映选择性CH代表手性碳-碳骨架的构建中最有效的原子路线,这是有机合成的主要研究课题。我们在此报告了2-甲基氮杂芳烃(例如2-甲基吡啶)的对映选择性钇催化的C(sp 3)-H键加成到各种取代的环丙烯和降冰片烯上。此过程有效地提供了高收率和高对映选择性(高达ee高达97%)的手性吡啶基甲基官能化的环丙烷和降冰片烷衍生物新家族。