Synergistic <i>N</i>-Heterocyclic Carbene/Palladium-Catalyzed [3 + 2] Annulation of Vinyl Enolates with 1-Tosyl-2-vinylaziridine
作者:Jian Gao、Jianming Zhang、Shuaishuai Fang、Jie Feng、Tao Lu、Ding Du
DOI:10.1021/acs.orglett.0c02935
日期:2020.10.2
(E)-3-ethylidene-4-vinylpyrrolidin-2-ones in a regioselective and stereoselective manner. The preliminary asymmetric studies were also performed, which indicated a potential for enantioselective annulation of vinyl enolate intermediates with transition-metal−π-allyl species.
cathode surface, protonation, and radical cross-coupling process, resulting in a variety of valuable pyridine variants, which contain a tertiary and even a quaternary carbon at the α-position of pyridines, in high yields. The employment of thioesters to the conjugated alkenes enables no requirement of catalyst and high temperature, representing a highly sustainable synthetic method.
Carbene-Catalyzed Formal [3+3] Cycloaddition Reaction for Access to Substituted 2-Phenylbenzothiazoles
作者:Zhibin Ni、Chengli Mou、Xun Zhu、Puying Qi、Song Yang、Yonggui Robin Chi、Zhichao Jin
DOI:10.1002/ejoc.201901773
日期:2020.1.31
carbene‐catalyzed oxidative cycloadditionreaction is developed for efficient access to multi‐functionalized 2‐phenylbenzothiazoles. A broad scope of heavily substituted arenes bearing 2‐benzothiazole groups have been prepared in good to excellent yields. The remote C(sp2)–H bond in the substituted arene products can be regioselectively activated by Pd catalysts with the direction of the 2‐benzothiazole groups
Rerouting Radical Cascades: Intercepting the Homoallyl Ring Expansion in Enyne Cyclizations via C–S Scission
作者:Sayantan Mondal、Brian Gold、Rana K. Mohamed、Hoa Phan、Igor V. Alabugin
DOI:10.1021/jo5012043
日期:2014.8.15
to 6-endo-trig selectivity in the radicalcyclization of aromatic enynes was probed via the combination of experimental and computational methods. This transformation occurs by kinetic self-sorting of the mixture of four equilibrating radicalsvia 5-exo-trig cyclization, followed by homoallyl (3-exo-trig/fragmentation) ring expansion to afford the benzylic radical necessary for the final aromatizing
Synthesis of 9,10-Phenanthrenes via Palladium-Catalyzed Aryne Annulation by <i>o</i>-Halostyrenes and Formal Synthesis of (±)-Tylophorine
作者:Tuanli Yao、Haiming Zhang、Yanna Zhao
DOI:10.1021/acs.orglett.6b00558
日期:2016.6.3
A novel palladium-catalyzedannulation reaction of in situ generated arynes and o-halostyrenes has been developed. This methodology affords moderate to excellent yields of substituted phenanthrenes and is tolerant of a variety of functional groups such as nitrile, ester, amide, and ketone. This annulation chemistry has been successfully applied to the formal total synthesis of a biologically active