Palladium(0)-Catalyzed Cross-Coupling of 1,1-Diboronates with Vinyl Bromides and 1,1-Dibromoalkenes
作者:Huan Li、Zhikun Zhang、Xianghang Shangguan、Shan Huang、Jun Chen、Yan Zhang、Jianbo Wang
DOI:10.1002/anie.201407000
日期:2014.10.27
Palladium‐catalyzed cross‐coupling reactions of 1,1‐diboronates with vinylbromides and dibromoalkenes were found to afford 1,4‐dienes and allenes, respectively. These reactions utilize the high reactivities of both 1,1‐diboronates and allylboron intermediates generated in the initial coupling.
Generation of Allenic/Propargylic Zirconium Complexes and Subsequent Cross-Coupling Reactions: A Facile Synthesis of Multisubstituted Allenes
作者:Hao Zhang、Xiaoping Fu、Jingjin Chen、Erjuan Wang、Yuanhong Liu、Yuxue Li
DOI:10.1021/jo9020419
日期:2009.12.18
The β-alkoxide elimination reaction of propargylic ether with Negishi reagent leads to allenes and/or alkynes after hydrolysis. The product distribution is highly dependent on the substitution pattern of starting propargylic ethers; that is, aryl- or alkyl-substituted propargylic ethers favor the allene products, whereas TMS-substituted propargylic ethers afford alkynes. DFT calculations revealed that
A new method for synthesis of allenes, including an optically active form, from aldehydes and alkenyl aryl sulfoxides by sulfoxide–metal exchange as the key reaction and an application to a total synthesis of male bean weevil sex attractant
The sulfoxide–metal exchange reaction of β-acetoxy sulfoxides or β-mesyloxy sulfoxides, which were derived from alkenyl aryl sulfoxides and aldehydes in two steps, with a Grignard reagent or alkyllithium at low temperature gave allenes in good yields. Optically active allenes were synthesized starting from optically active 2-substituted ethenyl p-tolyl sulfoxides. A synthesis of (−)-methyl (E)-2,4