N-sulfonyl 1-aminobut-3-yn-2-ones are converted into bicyclic indolizines and pyrrolo[1,2-a]azepine-type alkaloids upon gold(I) catalysis (17 examples, 10-85%). The reaction cascade allowed formation of C-N, O-S, and C-C bonds via a cycloisomerization/sulfonyl migration/cyclization process using 10 mol % of [(2-biphenyl)di-tert-butylphosphine]gold(I) triflimide complex in dichloromethane.
Silver-Catalyzed [2+1] Cyclopropenation of Alkynes with Unstable Diazoalkanes:<i>N</i>-Nosylhydrazones as Room-Temperature Decomposable Diazo Surrogates
作者:Zhaohong Liu、Qiangqiang Li、Peiqiu Liao、Xihe Bi
DOI:10.1002/chem.201605335
日期:2017.4.6
The [2+1] cycloaddition of alkynes with diazo compounds represents one of the most powerful and reliable methods for the construction of cyclopropenes. However, it remains a formidable challenge to accomplish the cyclopropenation of alkynes with non‐stabilized diazoalkanes, owing to the fact that such compounds are unstable and prone to detonation. Herein, we report a general silver‐catalyzed cyclopropenation
Itraconazole Side Chain Analogues: Structure–Activity Relationship Studies for Inhibition of Endothelial Cell Proliferation, Vascular Endothelial Growth Factor Receptor 2 (VEGFR2) Glycosylation, and Hedgehog Signaling
作者:Wei Shi、Benjamin A. Nacev、Blake T. Aftab、Sarah Head、Charles M. Rudin、Jun O. Liu
DOI:10.1021/jm200944b
日期:2011.10.27
analogues against VEGFR2 glycosylation was generally driven by sidechains of at least four carbons in composition with branching at the α or β position. SAR trends for targeting the Hh pathway were divergent from those related to HUVEC proliferation or VEGFR2 glycosylation. These results also suggest that modification of the sec-butyl sidechain can lead to enhancement of the biological activity of itraconazole
作者:Graham W. Skelton、Dewen Dong、Rachel P. Tuffin、Stephen M. Kelly
DOI:10.1039/b209045g
日期:2003.2.20
The first liquid crystals incorporating a non-conjugated carbon–carbon triple bond in the terminal chain to exhibit a nematic phase above the melting point are reported. A variety of compounds incorporating a carbon–carbon triple bond in the terminal chain or between two phenyl rings have been synthesised as part of an investigation of the effects of the shape, conformation and rigidity of the terminal chains of liquid crystals on their mesophase behaviour. A series of related tolanes incorporating an alkenyloxy chain with an additional carbon–carbon double bond or a simple alkoxy chain as a terminal substituent also were prepared for comparison purposes.
Regioselective Amine–Borane Cyclization: Towards the Synthesis of 1,2‐BN‐3‐Cyclohexene by Copper‐Assisted Triazole/Gold Catalysis
作者:Stephen E. Motika、Qiaoyi Wang、Novruz G. Akhmedov、Lukasz Wojtas、Xiaodong Shi
DOI:10.1002/anie.201604986
日期:2016.9.12
as the optimal catalytic system for promoting intramolecular hydroboration for the synthesis of a six‐membered cyclic amine–borane. Excellent yields (up to 95 %) and regioselectivities (5‐exo vs. 6‐endo) were achieved through catalyst control and sequential dilution. Good functional‐group tolerance was attained, thus allowing the preparation of highly functionalized cyclic amine–borane substrates,
三唑/金(TA-Au)和Cu(OTf)2的组合被认为是促进分子内氢硼化合成六元环胺-硼烷的最佳催化体系。通过催化剂控制和顺序稀释,获得了极高的收率(高达95%)和区域选择性(5-exo vs. 6-endo)。获得了良好的官能团耐受性,因此可以制备高度官能化的环胺-硼烷底物,而这是其他方法无法实现的。氘标记研究支持在金活化炔烃中加入氢化物并随后形成C-B键。