提出了金(I)催化烯丙醇和硫醇之间的直接硫醚化反应。该反应通常具有高度区域选择性(S N 2')。这种脱水烯丙基化过程非常温和且原子经济,仅产生水作为副产物,并避免与在底物上安装离去或活化基团相关的任何不必要的浪费/步骤。提出计算研究以深入了解反应机制。计算表明,区域选择性处于平衡控制之下,并且最终由产物的热力学稳定性决定。
Palladium-Catalyzed Synthesis of Conjugated Allenynes via Decarboxylative Coupling
作者:Mary K. Smith、Jon A. Tunge
DOI:10.1021/acs.orglett.7b01751
日期:2017.10.20
A new strategy to access conjugated allenynes via a decarboxylativecoupling of propargyl esters of propiolates has been developed. In this process, allenyl-palladium intermediates are coupled with acetylides that are generated in situ to form the conjugated allenynes. Finally, the coupling is demonstrated to be highly stereospecific, providing a route to enantioenriched allenes.
Alkylidenesilacyclopropanes Derived from Allenes: Applications to the Selective Synthesis of Triols and Homoallylic Alcohols
作者:Kay M. Buchner、Timothy B. Clark、Janice M. N. Loy、Thong X. Nguyen、K. A. Woerpel
DOI:10.1021/ol900456v
日期:2009.5.21
transfer to allenes. Oxasilacyclopentanes derived from allenes were prepared with high regio- and diastereoselectivity by a two-step, one-flask silacyclopropanation/carbonyl insertion reaction. Triols and homoallylic alcohols were formed diastereoselectively by functionalizing the oxasilacyclopentanes. An optically active allene (>98% ee) was utilized to synthesize an enantiopure homoallylic alcohol in 96%
几种亚烷基硅杂环丙烷是通过银介导的甲硅烷基转移到丙二烯来制备的。通过两步、单烧瓶硅杂环丙烷化/羰基插入反应,以高区域选择性和非对映选择性制备了衍生自丙二烯的氧硅杂环戊烷。通过对氧硅杂环戊烷进行官能化,非对映选择性地形成三醇和高烯丙醇。光学活性丙二烯 (>98% ee) 用于合成 96% ee 的对映纯高烯丙醇。
In Situ Generation of Nucleophilic Allenes by the Gold-Catalyzed Rearrangement of Propargylic Esters for the Highly Diastereoselective Formation of Intermolecular C(sp<sup>3</sup>)C(sp<sup>2</sup>) Bonds
作者:Yang Yu、Weibo Yang、Frank Rominger、A. Stephen K. Hashmi
DOI:10.1002/anie.201302402
日期:2013.7.15
particular for the synthesis of isochromane derivatives (see scheme), are provided by the title reaction. Excellent diastereoselectivites are achieved in this reaction which proceeds through a gold‐catalyzed 1,3‐acyloxy migration. In some cases exclusively the Z isomer is detected.
The cobalt-catalyzed carboxylation of propargyl acetates with CO2 (1 atm) is described. The reaction proceeds at room temperature in the presence of Mn powder as a reducing reagent. Various propargyl acetates are converted to the corresponding carboxylic acids in good to high yields.
An aqueous and recyclable copper(i)-catalyzed route to α-sulfenylated carbonyl compounds from propargylic alcohols and aryl thiols
作者:Rahul A. Watile、Srijit Biswas、Joseph S. M. Samec
DOI:10.1039/c3gc41251b
日期:——
A highly efficient one-step copper(I)-catalyzed method for the synthesis of α-sulfenylated carbonyl compounds frompropargylicalcohols and aryl thiols in aqueous media is described. A variety of α-sulfenylated carbonyl compounds can be synthesized in good to excellent yields. The catalyst has been successfully recycled up to 4 times without any loss of activity in an aqueous medium.