3899-20-5Relevant articles and documents
Iron-Catalyzed Vinylzincation of Terminal Alkynes
Huang, Qiang,Su, Yu-Xuan,Sun, Wei,Hu, Meng-Yang,Wang, Wei-Na,Zhu, Shou-Fei
, p. 515 - 526 (2022/01/08)
Organozinc reagents are among the most commonly used organometallic reagents in modern synthetic chemistry, and multifunctionalized organozinc reagents can be synthesized from structurally simple, readily available ones by means of alkyne carbozincation. However, this method suffers from poor tolerance for terminal alkynes, and transformation of the newly introduced organic groups is difficult, which limits its applications. Herein, we report a method for vinylzincation of terminal alkynes catalyzed by newly developed iron catalysts bearing 1,10-phenanthroline-imine ligands. This method provides efficient access to novel organozinc reagents with a diverse array of structures and functional groups from readily available vinylzinc reagents and terminal alkynes. The method features excellent functional group tolerance (tolerated functional groups include amino, amide, cyano, ester, hydroxyl, sulfonyl, acetal, phosphono, pyridyl), a good substrate scope (suitable terminal alkynes include aryl, alkenyl, and alkyl acetylenes bearing various functional groups), and high chemoselectivity, regioselectivity, and stereoselectivity. The method could significantly improve the synthetic efficiency of various important bioactive molecules, including vitamin A. Mechanistic studies indicate that the new iron-1,10-phenanthroline-imine catalysts developed in this study have an extremely crowded reaction pocket, which promotes efficient transfer of the vinyl group to the alkynes, disfavors substitution reactions between the zinc reagent and the terminal C–H bond of the alkynes, and prevents the further reactions of the products. Our findings show that iron catalysts can be superior to other metal catalysts in terms of activity, chemoselectivity, regioselectivity, and stereoselectivity when suitable ligands are used.
A cross-metathesis approach to the synthesis of new etretinate type retinoids, ethyl retinoate and its 9Z-isomer
Maj, Jadwiga,Morzycki, Jacek W.,Rárová, Lucie,Wasilewski, Grzegorz,Wojtkielewicz, Agnieszka
, p. 5430 - 5433 (2012/11/07)
Two aromatic retinoids were synthesized from styrene derivatives using a novel strategy with a cross-metathesis reaction as a key step. The biological activity of the new etretinate analogues was tested. Cross-metathesis reactions were also employed for the preparation of ethyl retinoate and its 9Z-isomer via the C15 + C5 route.
Cross metathesis of β-carotene with electron-deficient dienes. A direct route to retinoids
Wojtkielewicz, Agnieszka,Maj, Jadwiga,Morzycki, Jacek W.
supporting information; experimental part, p. 4734 - 4737 (2011/03/18)
Cross metathesis (CM) reactions of β-carotene and alkenes occur regioselectively in the presence of the Hoveyda second generation catalyst. Scission of the C15-C15′ and C11-C12 bonds of β-carotene in all CM reactions predominates. The reaction with ethyl
