Me<sub>2</sub>Zn-Mediated Addition of Acetylenes to Aldehydes and Ketones
作者:Pier Giorgio Cozzi、Jens Rudolph、Carsten Bolm、Per-Ola Norrby、Claudia Tomasini
DOI:10.1021/jo050115r
日期:2005.7.1
Contrary to expectations, commercially available 2 M Me2Zn in toluene is able to promote the addition of phenylacetylene to aldehydes and ketones. This reactivity is determined by a new, unprecedented mechanism, which involves activation of the zinc reagent via coordination with carbonyl substrates that behave “ligand like”. Broad scope, high tolerance to functional groups, and a simple procedure make
与预期相反,在甲苯中可商购的2 M Me 2 Zn能够促进将苯乙炔添加到醛和酮中。这种反应性是由一种新的,前所未有的机制决定的,该机制涉及通过与表现为“配体样”的羰基底物的配位来激活锌试剂。宽泛的范围,对官能团的高度耐受性以及简单的操作步骤使这种新方法对于合成化学家而言非常有趣。
The palladium-tributylammonium formate reagent in the stereoselective hydrogenation, and stereo- and regioselective hydroarylation of alkyl 4-hydroxy-2-alkynoates: a route to substituted butenolides
The reaction of aryl iodides with alkyl 4-hydroxy-2-alkynoates in the presence of formic acid, tri-n-butylamine and a palladium(II) catalyst provides a convenient route to functionalized substituted butenolides through a one pot hydroarylation/cyclization reaction. In the presence of formic acid, tri-n-butylamine and a palladium(II) catalyst, alkyl 4-hydroxy-2-alkynoates undergo a one pot hydrogenation/cyclization
Rhodium-catalysed redox isomerization of hydroxy alkynes to trans keto and hydroxy vinyl esters. A short and stereoselective synthesis of dipeptide isosters
作者:M.K. Eddine Saïah、Roberto Pellicciari
DOI:10.1016/0040-4039(95)00768-8
日期:1995.6
Tris(triphenylphosphine)Rhodium(I) Chloride in the presence trialkyl phosphine catalyses the isomerization of hydroxy alkynes to unsaturated trans keto and hydroxy esters depending on the nature of the phosphine. Dipeptide isosters were obtained in a an efficient manner by the application of this methodology.
An Alkyne Hydroacylation Route to Highly Substituted Furans
作者:Philip Lenden、David A. Entwistle、Michael C. Willis
DOI:10.1002/anie.201105795
日期:2011.11.4
More rings for your rhodium: Rhodium‐catalyzed intermolecularalkynehydroacylations deliver γ‐hydroxy‐α,β‐enones, which can be cyclized in situ to deliver di‐ and trisubstituted furans. Functionalization of the intermediates using Heck chemistry allows the formation of regioisomeric furans. The use of an alternative RhI catalyst delivers 1,4‐dicarbonyl compounds and hence pyrroles, thiophenes, and
Ruthenium-Catalyzed [2 + 2] Cycloadditions between Norbornene and Propargylic Alcohols or Their Derivatives
作者:Gavin C. Tsui、Karine Villeneuve、Emily Carlson、William Tam
DOI:10.1021/om500563h
日期:2014.7.28
Diastereoselective ruthenium-catalyzed [2 + 2] cycloadditions of norbornene and propargylic alcohols or their derivatives were investigated. The cycloadditions were found to be highly stereoselective, giving exo cycloadducts in moderate to excellent yields with diastereoselectivities up to 92:8. When a chiral propargylic alcohol was used in the cycloaddition, up to 80% ee of the [2 + 2] cycloadducts was