Synthesis of (±)-Bakuchiol via a Pot-Economy Approach
摘要:
AbstractA rapid synthetic route toward (±)‐Bakuchiol is presented in 29% overall yield. After the sole all‐carbon quaternary carbon center is created via allylboration of 2‐aryl acetaldehyde, a "Pot‐Economy" approach including mesylation, elimination, and desilylation was realized in the presence of tBuOK under ambient temperature to provide (±)‐Bakuchiol.
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。
Copper-Catalyzed Regiodivergent Silacarboxylation of Allenes with Carbon Dioxide and a Silylborane
A regiodivergent silacarboxylation of allenes under a CO2 atmosphere with PhMe2Si-B(pin) as a silicon source in the presence of a copper catalyst at 70 °C has been developed. The regioselectivity of the reaction is successfully reversed by the proper choice of ligand; carboxylated vinylsilanes are obtained with rac-Me-DuPhos as the ligand, whereas the use of PCy3 affords carboxylated allylsilanes.
在 70 °C 下,在铜催化剂存在下,以 PhMe2Si-B(pin) 作为硅源,在 CO2 气氛下开发了丙二烯的区域发散硅羧化反应。反应的区域选择性通过适当的配体选择成功逆转; 使用 rac-Me-DuPhos 作为配体获得羧化乙烯基硅烷,而使用 PCy3 获得羧化烯丙基硅烷。因此,可以从单个丙二烯底物选择性地和区域发散地合成两种不同的羧化硅烷。
Preparation of 1,2-Dienes by the Palladium-Catalyzed Hydrogenolysis of 3-Methoxycarbonyloxy-1-alkynes with Ammonium Formate
作者:Jiro Tsuji、Teruo Sugiura、Ichiro Minami
DOI:10.1055/s-1987-28020
日期:——
A useful preparative method for 1,2-dienes from 3-methoxy-carbonyloxy-1-alkynes by the palladium-catalyzed hydrogenolysis with ammonium formate is described. 3-Methoxycarbonyloxy-1-alkynes are prepared by the addition of magnesium acetylide to ketones or aldehydes, followed by quenching with methyl chloroformate.
Copper-catalyzed C–C bond-forming transformation of CO<sub>2</sub> to alcohol oxidation level: selective synthesis of homoallylic alcohols from allenes, CO<sub>2</sub>, and hydrosilanes
A highly selective carbon-carbon bond-forming transformation of carbon dioxide (CO2) to the alcoholoxidation level has been disclosed. By employing a copper/bisphosphine catalyst system and hydrosilanes as the mild and...
Use of Formate Salts as a Hydride and a CO<sub>2</sub> Source in <i>PGeP</i>-Palladium Complex-Catalyzed Hydrocarboxylation of Allenes
作者:Chuan Zhu、Jun Takaya、Nobuharu Iwasawa
DOI:10.1021/acs.orglett.5b00692
日期:2015.4.3
Use of formate salts as a hydride as well as a CO2 source was achieved in a PGeP-palladium complex-catalyzed hydrocarboxylation of allenes through a highly efficient decarboxylationcarboxylation process. This reaction proceeds under mild conditions and provides an alternative strategy for utilizing formate salts as a C1 source.