We present an easy and straightforward synthesis of 3-arylpyrrolines 4a-g by repeated treatment of 4-aryl-1,2,5,6-tetrahydropyridines 2a-g with in-chloroperoxybenzoic acid (MCPBA) and boron trifluoride etherate (BF3-OEt2). The transformation proceeds via epoxidation, ring contraction, Baeyer-Villiger oxidation and elimination reaction and affords 3-arylpyrrolines 4a-g with 61-70% yield. This facile strategy was also used to synthesize racemic baclofen (6). (c) 2005 Elsevier Ltd. All rights reserved.
作者:Rui Wang、Yi Chen、Mao Shu、Wenwen Zhao、Maoling Tao、Chao Du、Xiaoya Fu、Ao Li、Zhihua Lin
DOI:10.1002/chem.201905199
日期:2020.2.11
Compared with the ripeness of olefin metathesis, exploration of the construction of carbon-carbon double bonds through the catalytic carbonyl-olefin metathesis reaction remains stagnant and has received scant attention. Herein, a highly efficient AuCl3 -catalyzed intramolecular ring-closing carbonyl-olefin metathesis reaction is described. This method features easily accessible starting materials,
作者:Tuong Anh To、Chao Pei、Rene M. Koenigs、Thanh Vinh Nguyen
DOI:10.1002/anie.202117366
日期:2022.3.21
H-bonding network: Hexafluoroisopropanol (HFIP) can act as a hydrogen-bond donor to enhance the catalytic efficiency of simple Brønsted acid catalysts in carbonyl-olefin metathesis reactions by stabilization of all transition states and intermediates along the reaction pathway.
作者:Lina Ma、Wenjuan Li、Hui Xi、Xiaohui Bai、Enlu Ma、Xiaoyu Yan、Zhiping Li
DOI:10.1002/anie.201604349
日期:2016.8.22
carbonyl–olefin metathesis is an ongoing challenge in organic synthesis. Reported herein is an FeCl3‐catalyzedring‐closing carbonyl–olefin metathesis. The protocol allows access to a range of carbo‐/heterocyclic alkenes with good efficiency and excellent trans diastereoselectivity. The methodology presents one of the rare examples of catalytic ring‐closing carbonyl–olefin metathesis. This process is
The carbonyl–olefin metathesis (COM) reaction is an attractive approach for the formation of a new carbon–carbon double bond from a carbonyl precursor. In principle, this reaction can be promoted by the activation of the carbonyl group with a Brønsted acid catalyst; however, it is often complicated as a result of unwanted side reactions under acidic conditions. Thus, there have been only a very few
羰基-烯烃复分解 (COM) 反应是从羰基前体形成新的碳-碳双键的一种有吸引力的方法。原则上,该反应可以通过用布朗斯台德酸催化剂活化羰基来促进;然而,由于在酸性条件下发生不希望的副反应,它通常很复杂。因此,只有极少数的布朗斯台德酸催化 COM 反应的例子,所有这些都需要专门设计的装置。在此,我们报告了一种新的实用均相布朗斯台德酸催化方案,该方案使用硝基甲烷(一种容易获得的溶剂)来促进分子内闭环 COM 反应。