1453164-65-2Relevant academic research and scientific papers
Palladium-Catalyzed Oxidative Cross-Coupling of Conjugated Enynones with Organoboronic Acids
Xia, Ying,Ge, Rui,Chen, Li,Liu, Zhen,Xiao, Qing,Zhang, Yan,Wang, Jianbo
, p. 7856 - 7864 (2015)
A palladium-catalyzed oxidative cross-coupling reaction of conjugated enynones with organoboronic acids is developed. This reaction provides an efficient methodology for the synthesis of functionalized furan derivatives, including 2-alkenylfurans and furan-substituted 1,3-dienes. Palladium-carbene migratory insertion is proposed as the key step in these transformations. Notably, the β-hydride elimination process occurs in a stereoselective manner, resulting in the formation of double bonds with high (E)-selectivity.
Palladium-catalyzed carbene migratory insertion using conjugated ene-yne-ketones as carbene precursors
Xia, Ying,Qu, Shuanglin,Xiao, Qing,Wang, Zhi-Xiang,Qu, Peiyuan,Chen, Li,Liu, Zhen,Tian, Leiming,Huang, Zhongxing,Zhang, Yan,Wang, Jianbo
, p. 13502 - 13511 (2013/09/24)
Palladium-catalyzed cross-coupling reactions between benzyl, aryl, or allyl bromides and conjugated ene-yne-ketones lead to the formation of 2-alkenyl-substituted furans. This novel coupling reaction involves oxidative addition, alkyne activation-cyclization, palladium carbene migratory insertion, β-hydride elimination, and catalyst regeneration. Palladium (2-furyl)carbene is proposed as the key intermediate, which is supported by DFT calculations. The palladium carbene character of the key intermediate is validated by three aspects, including bond lengths, Wiberg bond order indices, and molecular orbitals, by comparison to those reported for stable palladium carbene species. Computational studies also revealed that the rate-limiting step is ene-yne-ketone cyclization, which leads to the formation of the palladium (2-furyl)carbene, while the subsequent carbene migratory insertion is a facile process with a low energy barrier (5 kcal/mol).
