14271-34-2Relevant academic research and scientific papers
Synergistic N-Heterocyclic Carbene/Palladium-Catalyzed [3 + 2] Annulation of Vinyl Enolates with 1-Tosyl-2-vinylaziridine
Gao, Jian,Zhang, Jianming,Fang, Shuaishuai,Feng, Jie,Lu, Tao,Du, Ding
, p. 7725 - 7729 (2020/10/09)
The synergistic combination of N-heterocyclic carbene organocatalysis and transition-metal catalysis for a formal [3 + 2] annulation between 3-substituted but-2-enoates and 1-tosyl-2-vinylaziridine was developed. This cooperative strategy provides a facile and efficient access to various functionalized (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.
Construction of Multi-Substituted Benzenes via NHC-Catalyzed Reactions of Carboxylic Esters
Wu, Jichang,Mou, Chengli,Chi, Yonggui Robin
, p. 333 - 337 (2018/03/07)
A carbene-catalyzed ester activation reaction for the synthesis of multi-substituted benzenes is developed. Tetra-substituted benzene compounds are efficiently synthesized through this methodology. Compared with aldehyde substrates used in previous reports, the ester substrates used here are much more readily available and inexpensive. In addition, the TEMPO oxidant used here is more inexpensive than the quinones commonly used in related carbene-catalyzed reactions.
Iridium(III)-Catalyzed Direct Arylation of C-H Bonds with Diaryliodonium Salts
Gao, Pan,Guo, Wei,Xue, Jingjing,Zhao, Yue,Yuan, Yu,Xia, Yuanzhi,Shi, Zhuangzhi
supporting information, p. 12231 - 12240 (2015/10/12)
By developing a new Ir(III)-catalyzed C-C cross-coupling, a versatile method for direct arylation of sp2 and sp3 C-H bonds in ketoximes, nitrogen-containing heterocycles, various arenes, and olefins has been established. The key to this arylation depends on the appropriate choice of catalyst and the use of diaryliodonium triflate salts as the coupling partners. This transformation has good functional group compatibility and can serve as a powerful synthetic tool for late-stage C-H arylation of complex compounds. Mechanistic studies by density functional theory calculations suggested that the sp3 C-H activation was realized by a triflate-involved concerted metalation-deprotonation process, and the following oxidation of Ir(III) to Ir(V) is the most favorable when a bistriflimide is contained in the diaryliodonium salt. Calculations indicated that both steps are enabled by initial anion exchange between the reactant complexes.
N-Heterocyclic Carbene-Catalyzed Activation of Esters of N-Hydroxyphthalimide: A Highly Enantioselective Route to Chiral Dihydropyridinones Bearing an All Carbon Quaternary Stereogenic Center
Zhang, Zhiming,Zeng, Xiaofei,Xie, Danbo,Chen, Dongdong,Ding, Liyuan,Wang, Anna,Yang, Limin,Zhong, Guofu
, p. 5052 - 5055 (2015/11/03)
An N-heterocyclic carbene-catalyzed highly enantioselective [3 + 3] annulation reaction of N-hydroxyphthalimide (NHPI) 3,3-disubstituted acrylates and N-Ts ketimines was developed. In most cases, the desired chiral dihydropyridinone products bearing an all carbon quaternary stereogenic center could be obtained in good yields with excellent enantioselectivities (>99% ee's), which demonstrated the NHPI acrylates as a kind of excellent substrate in NHC-catalysis.
N-heterocyclic carbene-catalyzed cyclization of unsaturated acyl chlorides and ketones
Shen, Li-Tao,Shao, Pan-Lin,Ye, Song
, p. 1943 - 1948 (2011/10/13)
A straightforward synthesis of optically active trifluoromethyl dihydropyranones and spirocyclic oxindole-dihydropyranones has been realized by the chiral N-heterocyclic carbenes-catalyzed cyclization of α,β- unsaturated β-methylacyl chlorides with activated trifluoromethyl ketones or isatin derivatives. Copyright
