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.
Palladium‐ and Rhodium‐Catalyzed Dynamic Kinetic Resolution of Racemic Internal Allenes Towards Chiral Pyrazoles
作者:Lukas J. Hilpert、Simon V. Sieger、Alexander M. Haydl、Bernhard Breit
DOI:10.1002/anie.201812984
日期:2019.3.11
resolution (DKR) of racemic allenes leading to N‐allylated pyrazoles is described. Such compounds are of enormous interest in medicinal chemistry as certified drugs and potential drug candidates. The new methods feature high chemo‐, regio‐ and enantioselectivities aside from displaying a broad substrate scope and functional group compatibility. A mechanistic rational accounting for allene racemization and trans‐alkene
Hydrocarboxylation of Allenes with CO<sub>2</sub> Catalyzed by Silyl Pincer-Type Palladium Complex
作者:Jun Takaya、Nobuharu Iwasawa
DOI:10.1021/ja806677w
日期:2008.11.19
complex-catalyzed hydrocarboxylation of allenes under carbon dioxide to give synthetically useful beta,gamma-unsaturated carboxylic acids was developed. This novel CO2-fixation reaction is thought to proceed through the catalytic generation of sigma-allyl palladium species via hydropalladation of allenes, followed by its regioselective nucleophilic addition to CO2 in the presence of an appropriate
开发了三齿 PSiP 钳形钯配合物在二氧化碳下催化丙二烯加氢羧化,得到合成有用的 β, γ-不饱和羧酸。这种新型的 CO2 固定反应被认为是通过丙二烯的氢化钯催化生成 σ-烯丙基钯物种,然后在适当的还原剂存在下将其区域选择性亲核加成到 中进行的。该反应成功应用于带有酯、氨基甲酸酯、酮和烯烃等官能团的各种丙二烯,显示出该方案的高合成效用。
Gold(I)-Catalyzed Rearrangement of Propargyl Benzyl Ethers: A Practical Method for the Generation and in Situ Transformation of Substituted Allenes
作者:Benoit Bolte、Yann Odabachian、Fabien Gagosz
DOI:10.1021/ja1020469
日期:2010.6.2
of benzyl propargyl ethers react with a gold(I) catalyst to furnish variously substituted allenes via a 1,5-hydride shift/fragmentation sequence. This transformation is rapid and practical. It can be performed under very mild conditions (room temperature or 60 degrees C) using terminal as well as substituted alkyne substrates bearing a primary, secondary, or tertiary benzyl ether group. The allenes
Efficient Generation and Increased Reactivity in Cationic Gold via Brønsted Acid or Lewis Acid Assisted Activation of an Imidogold Precatalyst
作者:Junbin Han、Naoto Shimizu、Zhichao Lu、Hideki Amii、Gerald B. Hammond、Bo Xu
DOI:10.1021/ol501443m
日期:2014.7.3
Brønsted or Lewis acid assisted activation of an imidogold precatalyst (L-Au-Pht, Pht = phthalimide) offers a superior way to generate cationic gold compared with the commonly used silver-based system. It is also broadly applicable for most common gold-catalyzed reactions. For reactions that require milder conditions, milder acids can be used for optimized efficiency.