199277-23-1Relevant articles and documents
Br?nsted Base-Catalyzed Umpolung Intramolecular Cyclization of Alkynyl Imines
Kondoh, Azusa,Terada, Masahiro
, p. 3998 - 4001 (2018)
A novel “umpolung” intramolecular cyclization of alkynyl imines, in which the electrophilic imine sp2-carbon formally serves as a nucleophilic site, was developed under Br?nsted base catalysis. The reaction involves the unprecedented catalytic generation of α-aminoester enolates from α-iminoesters via the 1,2-addition of the anion of a secondary phosphite to an imine moiety followed by the [1,2]-rearrangement of a dialkoxyphosphoryl moiety from carbon to nitrogen, which is a formal umpolung process, and the intramolecular addition to an alkyne. This is a rare example of a [1,2]-rearrangement of a dialkoxyphosphoryl moiety from carbon to nitrogen to generate an α-amino carbanion and the first catalytic carbon–carbon bond forming reaction utilizing the resulting carbanion as a nucleophile.
Cyclization of Alkyne-Azide with Isonitrile/CO via Self-Relay Rhodium Catalysis
Zhang, Zhen,Xiao, Fan,Huang, Baoliang,Hu, Jincheng,Fu, Bin,Zhang, Zhenhua
supporting information, p. 908 - 911 (2016/03/15)
A self-relay rhodium(I)-catalyzed cyclization of alkyne-azides with two σ-donor/π-acceptor ligands (isonitriles and CO) to form sequentially multiple-fused heterocycle systems via tandem nitrene transformation and aza-Pauson-Khand cyclization has been dev
Umpolung reactivity of indole through gold catalysis
Lu, Biao,Luo, Yingdong,Liu, Lianzhu,Ye, Longwu,Wang, Yanzhao,Zhang, Liming
supporting information; experimental part, p. 8358 - 8362 (2011/10/31)
Electrophilic indole? Indoles, which are typically nucleophilic, can be made electrophilic through gold catalysis. By using an ortho-azido group to deliver a nitrene intramolecularly, an arylalkyne is converted into a gold carbene intermediate containing an indole skeleton that is highly electrophilic at the 3-position. A range of functionalized indoles is readily accessed by utilizing this strategy.