Synthesis of Sulfur-Containing Heterocycles through Oxidative Carbon–Hydrogen Bond Functionalization
摘要:
Vinyl sulfides react rapidly and efficiently with 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) to form alpha,beta-unsaturated thiocarbenium ions through oxidative carbon-hydrogen bond cleavage. These electrophiles couple with appended pi-nucleophiles to yield sulfur-containing heterocycles through carbon-carbon bond formation. Several nucleophiles are compatible with the procedure, and the reactions generally proceed through readily predictable transition states.
Synthesis of Sulfur-Containing Heterocycles through Oxidative Carbon–Hydrogen Bond Functionalization
摘要:
Vinyl sulfides react rapidly and efficiently with 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) to form alpha,beta-unsaturated thiocarbenium ions through oxidative carbon-hydrogen bond cleavage. These electrophiles couple with appended pi-nucleophiles to yield sulfur-containing heterocycles through carbon-carbon bond formation. Several nucleophiles are compatible with the procedure, and the reactions generally proceed through readily predictable transition states.
Rational Design of a Second Generation Catalyst for Preparation of Allylsilanes Using the Silyl-Heck Reaction
作者:Jesse R. McAtee、Glenn P. A. Yap、Donald A. Watson
DOI:10.1021/ja505446y
日期:2014.7.16
second-generation ligand, bis(3,5-di-tert-butylphenyl)(tert-butyl)phosphine, for the preparation of allylsilanes using the palladium-catalyzed silyl-Heck reaction. This new ligand provides nearly complete suppression of starting material alkene isomerization that was observed with our first-generation catalyst, providing vastly improved yields of allylsilanes from simple alkene starting materials.
使用合理的配体设计,我们开发了第二代配体,双(3,5-二叔丁基苯基)(叔丁基)膦,用于使用钯催化的甲硅烷基-Heck 反应制备烯丙基硅烷。这种新的配体几乎完全抑制了我们的第一代催化剂所观察到的原料烯烃异构化,大大提高了从简单烯烃原料中获得的烯丙基硅烷的产率。描述了量化新配体的电子和空间特性的研究。最后,我们报告了使用类似配体氧化加成 Me3SiI 产生的钯络合物的 X 射线晶体结构,该结构提供了对催化系统性质的重要洞察。
Preparation of Allyl and Vinyl Silanes by the Palladium-Catalyzed Silylation of Terminal Olefins: A Silyl-Heck Reaction
作者:Jesse R. McAtee、Sara E. S. Martin、Derek T. Ahneman、Keywan A. Johnson、Donald A. Watson
DOI:10.1002/anie.201200060
日期:2012.4.10
high‐yielding protocol for the palladium‐catalyzed silylation of terminal alkenes is reported. This method allows facileconversion of styrenes to E‐β‐silyl styrenes by using iodotrimethylsilane (TMSI) or chlorotrimethylsilane/lithium iodide (see scheme). Terminal allyl silanes with good E/Z ratios are also readily accessed from α‐olefins.