Novel multi-dentate phosphines for Pd-catalyzed alkoxycarbonylation of alkynes promoted by H2O additive
作者:Da Yang、Lei Liu、Dong-Liang Wang、Yong Lu、Xiao-Li Zhao、Ye Liu
DOI:10.1016/j.jcat.2019.01.031
日期:2019.3
A series of novel multi (bi-/tri-/tetra-)-dentate phosphines with good robustness against water and oxygen were synthesized and fully characterized. It was found that the developed ionic tri-dentate phosphine (L2′) enabled Pd-catalyzed alkoxycarbonylation of alkynes most efficiently while H2O was used as an additive instead of acid. As for L2′, its unique steric configuration with two types of potential
The decarbonylation of primary, secondary, and tertiary alkyl-substituted acyl radicals has been investigated through photoredoxcatalysis. A series of quaternary carbons and γ-ketoesters have been directly constructed by the photoredox 1,4-conjugate addition of the corresponding alkyl ketoacids with electrophilic alkenes. And, the tertiary alkyl ketoacids have proved to be good precursors of tertiary
In the work reported herein, the concise and enantioselective total synthesis of the Schizozygine alkaloid (−)-strempeliopine was developed. This synthetic strategy featured the palladium-catalyzed decarboxylative asymmetric allylic alkylation of N-benzoyl lactam to set up the absolute configuration at the C20 position, a highly diastereoselective one-pot Bischler–Napieralski/lactamization and iminium
An efficient rhodium-catalyzed protocol for the synthesis of cyclopentenones based on a three-component reaction of acrylic acids, formaldehyde, and malonates via vinylic C–H activation is reported. Exploratory studies showed that 5-alkylation of as-prepared cyclopentenones could be realized smoothly by the treatment of a variety of alkyl halides with a Na2CO3/MeOH solution. Excess formaldehyde and
报道了一种有效的铑催化合成环戊烯酮的方案,该方案基于丙烯酸、甲醛和丙二酸酯通过乙烯基 C-H 活化的三组分反应。探索性研究表明,通过用 Na 2 CO 3 /MeOH 溶液处理各种烷基卤化物,可以顺利地实现所制备的环戊烯酮的 5-烷基化。过量的甲醛和丙二酸酯导致多组分反应,通过迈克尔加成得到多取代的环戊烯酮。