New synthetic technology for the construction of N-hydroxyindoles and synthesis of nocathiacin I model systems
作者:K.C. Nicolaou、Anthony A. Estrada、Graeme C. Freestone、Sang Hyup Lee、Xavier Alvarez-Mico
DOI:10.1016/j.tet.2007.03.072
日期:2007.7
nucleophilic additions to in situ generated alpha,beta-unsaturated nitrones (III) through carbon-carbon and carbon-heteroatom bond formation. The new synthetic technology was applied to the synthesis of nocathiacinI (1) modelsystems (2 and 3a-c) containing the N-hydroxyindole structural motif.
Difluoroenol silyl ethers 5 and 6, difluoroketene silyl (O,O-, O,S-, and O,N-) acetals 9 and 21, and 2,2-difluoro-2-trimethylsilylacetates 10 were prepared by electroreductive defluorination of trifluoromethyl ketones and trifluoroaceticacidderivatives in an MeCN-TBAB-chlorotrialkylsilane system using a carbon rod as an anode and a lead plate as a cathode. TBAF- or KF-CuI-promoted alpha-alkylation
Visible-light-initiated difluoromethylation of arene diazonium tetrafluoroborates
作者:Ye-bin Wu、Guo-ping Lu、Bao-jing Zhou、Mei-jie Bu、Li Wan、Chun Cai
DOI:10.1039/c6cc00177g
日期:——
A mild and efficient method for the radical addition of [small alpha]-aryl-[small beta],[small beta]-difluoroenol silyl with arene diazonium tetrafluoroborates at room temperature has been disclosed, which contains an innate radical long chain cycle...
Organocatalytic asymmetric synthesis of 3-difluoroalkyl 3-hydroxyoxindoles
作者:Yun-Lin Liu、Jian Zhou
DOI:10.1039/c2cc17140f
日期:——
We report the first example of highly enantioselective organocatalytic synthesis of 3-difluoroalkyl substituted 3-hydroxyoxindoles. The total synthesis of the difluoro analogue of convolutamydine E was achieved by this method.
has been developed using either MeOH or H2O as the solvent, which constitutes a facile and efficient protocol for the solvent-controlled divergentsynthesis of five- and seven-membered S-heterocycles featuring a gem-difluoromethylene group. A gram-scale synthesis and the diversification of the product transformations to other difluorinated S-heterocycles further highlight its utility.
苯并[ b ]噻吩-2,3-二酮与二氟烯氧基硅烷的前所未有的无催化剂反应已开发使用MeOH或H 2 O作为溶剂,这构成了溶剂控制的五个发散合成的简便有效的方案- 和七元S -杂环,具有一个gem -二氟亚甲基基团。克级合成和产品向其他二氟化S-杂环转化的多样化进一步突出了其效用。