Carbon Homologation of 1-Alkynes Using Alkoxymethyl Esters Mediated by Dichlorobis(trifluoromethanesulfonato)titanium(IV)
作者:Yoo Tanabe
DOI:10.1246/bcsj.67.3309
日期:1994.12
Various 1-alkynes were converted to 1-alkoxy-3-chloro-2-alkenes using alkoxymethyl esters and dichlorobis(trifluoromethanesulfonato)titanium(IV) [TiCl2(OTf)2, titanium(IV) bis(triflate)]. This carbon homologation proceeded in the case of not only simple 1-alkynes but also for several 3- or 4-dimethylcarbamoyloxy-, 5-benzoyloxy-, 5-phenoxycarbonyloxy-, and 5-methoxycarbonyloxy-1-alkynes. Among them
Axial-to-Central Chirality Transfer for Construction of Quaternary Stereocenters via Dearomatization of BINOLs
作者:Xiao-Long Min、Xu-Ran Xu、Ying He
DOI:10.1021/acs.orglett.9b03558
日期:2019.11.15
All-carbonquaternary stereocenters are versatile building blocks, and their asymmetric construction has attracted much attention. Herein, we disclose an axial-to-central chirality transfer strategy for the synthesis of chiralquaternary stereocenters via dearomatization of (S)-BINOLs. The reaction proceeded smoothly with a wide range of propargyl carbonates to afford chiral spiro-compounds in high
Copper(I) Acetate: A Structurally Simple but Highly Efficient Dinuclear Catalyst for Copper-Catalyzed Azide-Alkyne Cycloaddition
作者:Changwei Shao、Guolin Cheng、Deyong Su、Jimin Xu、Xinyan Wang、Yuefei Hu
DOI:10.1002/adsc.200900768
日期:——
this article, the structurally well‐defined dinuclear complex copper(I) acetate was studied in detail and was developed as a highly practical and efficient catalyst for the copper(I)‐catalyzed azide‐alkyne cycloaddition. The “bare” phenylethynylcopper(I) (i.e., with no exogeneous ligands) was isolated as an intermediate, which can be converted into an active catalytic species by treatment with acetic
Ruthenium-catalyzed addition reaction of acetic acid to propargyl alcohol derivatives: reagents for palladium-catalyzed 2-acetoxyallylation of carbonucleophiles
作者:Yoji Hori、Take-aki Mitsudo、Yoshihisa Watanabe
DOI:10.1016/0022-328x(87)80312-1
日期:1987.4
A bis(η2-cyclooctadienyl)ruthenium/PCy3/maleic anhydride system catalyzes the addition reaction of aceticacid to propargyl alcohol derivatives at 80°C to give 2-acetoxyallyl derivatives with high selectivity in high yields. The 2-acetoxyallyl carbonates prepared react with carbonucleophiles in the presence of a catalytic amount of Pd(PPh3)4 to give a series of novel polyfunctional enol esters in good
A new furan annelation by the palladium-catalyzed reaction of 2-alkynyl carbonates with β-keto esters is described. The reaction proceeds under mild neutral conditions and hence unstable 3-alkylidene-2,3-dihydrofurans can be prepared in this way. Similarly, reaction of 2-(1-alkynyl)oxiranes with β-keto esters gives alkylidene furans.