Cascade Reactions: Catalytic Synthesis of Functionalized 1,3-Dihydroisobenzofuran and Tetrahydrofuran Derivatives by Sequential Nucleophilic Ring Opening-Heterocyclization- Oxidative Carbonylation of Alkynyloxiranes
作者:Nicola Della Ca'、Fabio Campanini、Bartolo Gabriele、Giuseppe Salerno、Chiara Massera、Mirco Costa
DOI:10.1002/adsc.200900436
日期:2009.10
Differently substituted alkynyloxiranes were efficiently converted into functionalized 1,3-dihydroisobenzofurans and tetrahydrofuran derivatives in fair to good yields by a new cascade reaction, consisting of a sequential nucleophilic ring opening–heterocyclization–oxidative carbonylation process. Reactions were carried out at 80–100 °C and under a 3:1 mixture of carbon monoxide and air (total pressure=32–42 atm
Electronic control of product distribution in the [5+5]-coupling of ortho-alkynylbenzaldehyde derivatives and γ,δ-unsaturated carbene complexes
作者:Alejandro Camacho-Davila、Lalith S.R. Gamage、Zhipeng Wang、James W. Herndon
DOI:10.1016/j.tet.2010.04.117
日期:2010.7
The coupling of highly oxygenated ortho-alkynylbenzaldehyde derivatives with gamma,delta-carbene complexes was evaluated systematically. In all of the electron-rich systems investigated the exclusive product of the reaction is the dihydrophenanthrene derivative. Only the extremely electron-withdrawing methanesulfonate group can prevent this process from occurring. The use of the base additive collidine resulted in a surprising yield enhancement but no other discernable effect on the course of the reaction. Dihydrophenanthrene formation was attributed to rapid dehydration after the opening of a benzo-oxanorbornene intermediate. (C) 2010 Elsevier Ltd. All rights reserved.
Total Synthesis of Antofine Using the Net [5+5]-Cycloaddition of γ,δ-Unsaturated Carbene Complexes and 2-Alkynylphenyl Ketones as a Key Step
作者:Alejandro Camacho-Davila、James W. Herndon
DOI:10.1021/jo061053n
日期:2006.8.1
A compound containing all of the carbons of the anticancer agent antofine was produced in a single step from the coupling of a γ,δ-unsaturated carbene complex with a 2-alkynylphenyl ketone derivative. Subsequent conversion to antofine was effected in three steps.