ylides derived from short-chain trialkylphosphines in the Wittig-type olefinationreactions toward the synthesis of alkenes, including stilbenes, styrenes, and 1,3-dienes, as well as reagents for homologation reactions, are described. The methods allow easy access to alkenes with high (E)-stereoselectivity in good yield. These reactions are conducted with weak bases in aqueous media, which allows easy
Nickel-Catalyzed Decarboxylative Alkenylation of Anhydrides with Vinyl Triflates or Halides
作者:Hui Chen、Shuhao Sun、Xuebin Liao
DOI:10.1021/acs.orglett.9b01048
日期:2019.5.17
Decarboxylative cross-coupling of aliphatic acid anhydrides with vinyl triflates or halides was accomplished via nickel catalysis. This methodology works well with a broad array of substrates and features abundant functional group tolerance. Notably, our approach addresses the issue of safe and environmental installation of methyl or ethyl group into molecular scaffolds. The method possesses high chemoselectivity
Iron-Catalyzed Vinylic C−H Alkylation with Alkyl Peroxides
作者:Liang Ge、Wujun Jian、Huan Zhou、Shaowei Chen、Changqing Ye、Fei Yu、Bo Qian、Yajun Li、Hongli Bao
DOI:10.1002/asia.201800534
日期:2018.9.4
are readily accessible from carboxylic acids, are utilized as general primary, secondary, and tertiary alkylating reagents for iron‐catalyzed vinylic C−H alkylation of vinyl arenes, dienes, and 1,3‐enynes. This transformation affords olefinic products in up to 98 % yield with high E/Z values. A broad range of functionalities, including carboxyl, boronic acid, methoxy, ester, amino, and halides, are
According to “integrated chemical process”, a novel one-pot process for construction of highly substituted allylic moieties has been achieved. A series of alkylation of allylic sulfones and palladium-catalyzed reductive desulfonylation by use of LiBHEt3 is integrated. The double alkylation furnishes more substituted olefins. Use of arylzinc compounds in place of the hydride enables electrophilic a
Highly Stereoselective and General Synthesis of (<i>E</i>)-Stilbenes and Alkenes by Means of an Aqueous Wittig Reaction
作者:James McNulty、Priyabrata Das
DOI:10.1002/ejoc.200900634
日期:2009.8
The chemoselective formation of trialkyl(benzylidene) ylides in water and their Wittigreaction with aromatic and aliphatic aldehydes provides a practical, stereoselective and environmentally benign route to valuable (E)-stilbenes and alkenes. The synthesis of the phytoalexin resveratrol is described. In addition, the method allows for a gram-scale synthesis of the anticancer agent DMU-212 utilizing