A Stereoconvergent Cyclopropanation Reaction of Styrenes
作者:Ana M. del Hoyo、Ana G. Herraiz、Marcos G. Suero
DOI:10.1002/anie.201610924
日期:2017.2
The first stereoconvergent cyclopropanation reaction by means of photoredox catalysis using diiodomethane as the methylene source is described. This transformation exhibits broad functional group tolerance and it is characterized by an excellent stereocontrol en route to trans‐cyclopropanes regardless of whether E‐ or Z‐styrene substrates were utilized.
Superelectrophilic Fe(III)–Ion Pairs as Stronger Lewis Acid Catalysts for (<i>E</i>)-Selective Intermolecular Carbonyl–Olefin Metathesis
作者:Haley Albright、Hannah L. Vonesh、Corinna S. Schindler
DOI:10.1021/acs.orglett.0c00917
日期:2020.4.17
intermolecular carbonyl–olefin metathesis reaction is described that relies on superelectrophilic Fe(III)-based ionpairs as stronger Lewis acid catalysts. This new catalytic system enables selective access to (E)-olefins as carbonyl–olefin metathesis products. Mechanistic investigations suggest the regioselective formation and stereospecific fragmentation of intermediate oxetanes to be the origin of this
描述了一种分子间羰基-烯烃复分解反应,该反应依赖于超亲电 Fe(III) 基离子对作为更强的路易斯酸催化剂。这种新的催化系统能够选择性地使用 ( E )-烯烃作为羰基-烯烃复分解产物。机理研究表明,中间体氧杂环丁烷的区域选择性形成和立体特异性断裂是这种选择性的来源。优化的条件适用于各种芳基醛和三取代烯烃,并在 28 个示例中得到证明,总产率高达 64%。
Process for the isomerization of aromatic alkenyl compounds
申请人:Rhone-Poulenc S. A.
公开号:US04138411A1
公开(公告)日:1979-02-06
Aromatic alkenyl compounds, for example, eugenol and safrole, are isomerized, for example to isoeugenol and isosafrole, by contact with a ruthenium or osmium catalyst.
of two different internal alkene isomers. The chromium catalyst, in the presence of HBpin/LiOtBu, enables the isomerization of alkenes over multiple carbon atoms to give the most thermodynamically stable isomers. The same catalyst allows for the selective isomerization of terminal alkenes over one carbon atom without an additive, exhibiting efficient and controllable alkene transposition selectivity
我们报告了一种单一的添加剂响应型铬催化系统,用于选择性生产两种不同的内部烯烃异构体中的任何一种。在 HBpin/LiO t Bu 存在下,铬催化剂能够使烯烃在多个碳原子上异构化,得到热力学最稳定的异构体。同一催化剂无需添加剂即可实现末端烯烃在一个碳原子上的选择性异构化,表现出高效且可控的烯烃转位选择性。
Polkanov, M. A.; Shapiro, I. O.; Chernoplekova, V. A., Journal of Organic Chemistry USSR (English Translation), 1988, vol. 24, # 6, p. 1123 - 1127
作者:Polkanov, M. A.、Shapiro, I. O.、Chernoplekova, V. A.、Shatenshtein, A. I.