Cobalt-Catalyzed gem-Cross-Dimerization of Terminal Alkynes
作者:Jia-Feng Chen、Changkun Li
DOI:10.1021/acscatal.9b05078
日期:2020.3.20
Transition-metal-catalyzed dimerization of two different terminalalkynes provides an atom-economic synthesis of valuable conjugated 1,3-enynes. Despite many catalyst systems developed, the state-of-the-art solutions are still limited to special alkynes. A practical catalyst, which could be used to cross-dimerize general aryl alkynes and aliphatic alkynes, is still highly desired. Herein we present
Regioselective Access to 3‐Ethylideneflavanones via Rhodium(I)‐Catalyzed 1,3‐Enyne Hydroacylation/Annulation Cascades
作者:Zhi‐Xin Chang、Fu‐Rong Li、Chengcai Xia、Fei Li、Hong‐Shuang Li
DOI:10.1002/adsc.202001565
日期:2021.3.16
The highly efficient synthesis of 3‐ethylideneflavanones throughsequential rhodium(I)‐catalyzed hydroacylation of terminal aryl‐substituted 1,3‐enynes with chelating aldehydes and annulation is described. This straightforward protocol highlights an unprecedented C3‐regioselective hydroacylation of 1,3‐enynes, excellent functional group compatibility, and complete atom economy.
(2-bromoethyl)diphenylsulfonium triflate to be a powerful vinylation reagent was determined by the Sonogashira cross-coupling reactions with terminal alkynes. The vinylation proceeded smoothly at 25 °C under Pd/Cu catalysis to afford a variety of 1- and 2-unsubstituted 1,3-enynes in moderate to excellent yields. This protocol represents the first application of (2-haloethyl)diphenylsulfonium triflate as a CH═CH2 transfer
Hydrogen-Mediated C−C Bond Formation: Catalytic Regio- and Stereoselective Reductive Condensation of α-Keto Aldehydes and 1,3-Enynes
作者:Hye-Young Jang、Ryan R. Huddleston、Michael J. Krische
DOI:10.1021/ja0316566
日期:2004.4.1
Hydrogenation of 1,3-enynes in the presence of alpha-keto aldehydes using cationic Rh(I) catalysts enables regio- and stereoselective reductivecoupling to the acetylenic terminus of the enyne to afford (E)-2-hydroxy-3,5-dien-1-one products. Reductive condensation of 1-phenyl but-3-en-1-yne 1a with phenyl glyoxal 2a performed under an atmosphere of D(2) provides the product of mono-deuteration, (E
Enantioselective Reductive Coupling of 1,3-Enynes to Glyoxalates Mediated by Hydrogen: Asymmetric Synthesis of β,γ-Unsaturated α-Hydroxy Esters
作者:Young-Taek Hong、Chang-Woo Cho、Eduardas Skucas、Michael J. Krische
DOI:10.1021/ol7015548
日期:2007.9.1
Catalytic hydrogenation of 1,3-enynes 1a-8a in the presence of ethyl glyoxalate at ambient pressure and temperature using a rhodium catalyst modified by (R)-(3,5-tBu-4-MeOPh)-MeO-BIPHEP results in highly regio- and enantioselective reductivecoupling to furnish the corresponding alpha-hydroxy esters 1b-8b. As demonstrated by the elaboration of alpha-hydroxy ester 1b, the terminal and internal olefin