52915-53-4Relevant academic research and scientific papers
Directing-group-assisted manganese-catalyzed cyclopropanation of indoles
Dutta, Pratip K.,Chauhan, Jyoti,Ravva, Mahesh Kumar,Sen, Subhabrata
, p. 2025 - 2028 (2019)
The first manganese-catalyzed cyclopropanation of indoles is reported in moderate to excellent yield with methyl-2-diazo-2-arylacetates. This new strategy involved acetyl (COCH3) as the directing group and exhibited exceptional functional group tolerance. In the absence of stereodirecting groups the desired products were obtained as a mixture of diastereomers (7:3 → 8:2). Control experiments and DFT studies elucidated the probable pathway for the formation of cyclopropane-fused indole product. Deacetylation of the final products afforded both C3-substituted NH-indoles.
Enantioselective Indole Insertion Reactions of α-Carbonyl Sulfoxonium Ylides
Burtoloso, Antonio C. B.,Echemendía, Radell,Leveille, Alexandria N.,Mattson, Anita E.
supporting information, p. 9446 - 9450 (2021/12/14)
The first example of organocatalytic enantioselective C–H insertion reactions of indoles and sulfoxonium ylides is reported. Under the influence of phosphoric acid catalysis, levels of enantiocontrol in the range of 20–93% ee and moderate yields (up to 50
Metal-Free Insertion of Sulfoxonium Ylides into Arylamines in Water
He, Hua,Yan, Kaichuan,Li, Jianglian,Lai, Ruizhi,Luo, Yi,Guan, Mei,Wu, Yong
, p. 3065 - 3070 (2020/08/10)
Carbenoid-based N-H insertions have undergone significant development with respect to C-N bond formation in recent years. However, the existing methods suffer from unstable starting materials, expensive metal catalysts and organic solvents. Herein, insertion of sulfoxonium ylides into arylamines under metal-free conditions has been developed. The method employs water as solvent at mild temperature and is amenable to the late-stage modification of structurally complex bioactive compounds.
Catalytic functionalization of indoles by copper-mediated carbene transfer
Delgado-Rebollo, Manuela,Prieto, Auxiliadora,Perez, Pedro J.
, p. 2047 - 2052 (2014/08/05)
The complex [TpBr3Cu(NCMe)] (TpBr3=hydrotris(3,4,5- tribromo)pyrazolylborate) efficiently catalyzes the C-H functionalization of indole derivatives at C3 by carbene transfer from different diazoesters in a high-yield transformation involving low catalyst loadings and short reaction times. This system has shown that the previously proposed dichotomy of carbene addition (to the double bond) vs carbene insertion (to the C-H bond) corresponds to two consecutive reaction steps: the cyclopropane intermediates, observed in the reaction mixtures, are the precursors of the final C-H functionalization derivatives in a ring-opening process involving acid catalysis. Those in situ generated cyclopropanes undergo nucleophilic ring opening with Me 2CuLi to afford both C2 and C3 functionalized indoles.
