Cyclization of Gold Acetylides: Synthesis of Vinyl Sulfonates via Gold Vinylidene Complexes
作者:Janina Bucher、Thomas Wurm、Kumara Swamy Nalivela、Matthias Rudolph、Frank Rominger、A. Stephen K. Hashmi
DOI:10.1002/anie.201310280
日期:2014.4.7
Differently substituted terminal alkynes that bear sulfonate leaving groups at an appropriate distance were converted in the presence of a propynyl gold(I) precatalyst. After initial formation of a gold acetylide, a cyclization takes place at the β‐carbon atom of this species. Mechanistic studies support a mechanism that is related to that of dual gold‐catalyzed reactions, but for the new substrates
Catalytic Transformations of Alkynes into either α-Alkoxy or α-Aryl Enolates: Mannich Reactions by Cooperative Catalysis and Evidence for Nucleophile-Directed Chemoselectivity
作者:Rajkumar Lalji Sahani、Manoj D. Patil、Sachin Bhausaheb Wagh、Rai-Shung Liu
DOI:10.1002/anie.201806883
日期:2018.11.5
The catalytic formation of gold enolatesfrom alkynes, nitrones, and nucleophiles is described, and their Mannich reactions result in nucleophile‐directed chemoselectivity through cooperative catalysis. For 1‐alkyn‐4‐ols and 2‐ethynylphenols, their gold‐catalyzed nitrone oxidations afforded N‐containing dihydrofuran‐3(2H)‐ones with syn selectivity. The mechanism involves the Mannich reactions of gold
Silver-catalyzed synthesis of 4-substituted benzofurans<i>via</i> a cascade oxidative coupling-annulation protocol
作者:Yang Ye、Renhua Fan
DOI:10.1039/c1cc10137d
日期:——
A facile synthesis of 4-indole benzofurans via an oxidative dearomatization, a silver-catalyzed cascade Michael addition-annulation, and an aromatization is reported.
通过氧化脱芳构建的银催化级联迈克尔加成-环化和芳香化,报告了一种简便的4-吲哚苯并呋喃合成。
OPHTHALMIC LENS MATERIALS CONTAINING CHROMOPHORES THAT ABSORB BOTH UV AND SHORT WAVELENGTH VISIBLE LIGHT
申请人:Weinschenk, III Joseph I.
公开号:US20090043007A1
公开(公告)日:2009-02-12
Chromophores that absorb both UV and short wavelength visible light are disclosed. The chromophores are particularly suitable for use in intraocular lens materials.
吸收紫外线和短波长可见光的色素团被披露。这些色素团特别适用于人工晶状体材料。
A Hg(OTf)<sub>2</sub>-Catalyzed Enolate Umpolung Reaction Enables the Synthesis of Coumaran-3-ones and Indolin-3-ones
作者:Zhouting Rong、Weican Hu、Ning Dai、Guoying Qian
DOI:10.1021/acs.orglett.0c01096
日期:2020.4.17
The potential of mercury catalysis has been extended to the arena of enolate umpolung reactions for the first time by the generation of enolonium species via Hg(OTf)2-catalyzed N-oxide addition to alkynes. The enolonium species formed can undergo intramolecular nucleophilic attack by hydroxyl or amino groups, leading to the synthesis of various coumaran-3-ones and indolin-3-ones.