The umpolung of β,γ-unsaturated diketones through N-heterocyclic carbene catalysis is described, which allows access to a variety of highly functionalized bicyclic cyclohexene-β-lactones and 1,3,4-triaryl benzenes. An unprecedented reaction pattern involving the catalytic formation of nucleophilic O-acylated homoenolate intermediate is proposed. A diverse set of transformations on the product further
potential tubulininhibitors. These compounds displayed potent anti-proliferative activities (micromolar to nanomolar) against a panel of cancer cell lines (including HepG-2, HCT-116, A549 and MDA-MB-231 cells). Among them, compound TB-25 exhibited the strongest inhibitory effects against HCT-116 cells with an IC50 of 23 nM. Mechanism studies revealed that TB-25 could effectively inhibittubulin polymerization
The present invention relates to novel compounds having anti-cancer activity, methods of making these compounds, and their use for treating cancer and drug-resistant tumors, e.g. melanoma, metastatic melanoma, drug resistant melanoma, prostate cancer and drug resistant prostate cancer.
Selective oxidation of benzylic or allylic hydroxyl group of sec-1,2-diols
作者:Kun Peng、Fuxin Chen、Xuegong She、Chunhui Yang、Yuxin Cui、Xinfu Pan
DOI:10.1016/j.tetlet.2004.12.073
日期:2005.2
A mild and efficient method to selectively oxidize chiral sec-1,2-diols has been developed, which demonstrates that 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) can selectively oxidize benzylic or allylic hydroxyl group of sec-1,2-diols under ultrasound wave promotion. The configuration of the adjacent chiral center is retained. (C) 2004 Elsevier Ltd. All rights reserved.