visible-light photoredox catalysis. A variety of tetraalkyl ammonium salts, bearing primary, secondary, and tertiary C-N bonds, undergo selective couplings with aldehydes/ketone and CO2. Notably, the in situ generated byproduct, trimethylamine, is efficiently utilized as the electron donor. Moreover, this protocol exhibits mild reaction conditions, low catalyst loading, broad substrate scope, good
两个亲电子试剂之间的交叉亲电子试剂偶联是在化学计量外部还原剂存在下生成 CC 键的有效且经济的方法。在此,我们报告了一种通过可见光光氧化还原催化实现第一个无外部还原剂的交叉亲电子偶联的新策略。各种带有伯、仲和叔 CN 键的四烷基铵盐与醛/酮和 CO2 进行选择性偶联。值得注意的是,原位生成的副产物三甲胺被有效地用作电子供体。此外,该协议表现出温和的反应条件、低催化剂负载、广泛的底物范围、良好的官能团耐受性和容易的可扩展性。机理研究表明,苄基自由基和阴离子可能是通过光催化产生的关键中间体,
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。
New chiral polysiloxanes prepared from derivatives of (+)- or (-)-2-phenyl-3-butehoic acid, (r)-l-hepten-3-ol and (r)-l-cyclohexyl-2-propen-1-ol
作者:Sunil K. Aggarwal、Jerald S. Bradshaw、Masakatsu Eguchi、Scott Parry、Bryant E. Rossiter、Karin E. Markides、Milton L. Lee
DOI:10.1016/s0040-4020(01)89977-4
日期:1987.1
series of new polysiloxanes containing chiral side groups has been prepared. These polymers were prepared by hydrosilylating chiral alkene derivatives onto polyhydromethylsiloxane. The alkene derivatives were prepared from (+) or (-)-2-phenyl-3-butenoic acid, (R)-1-hepten-3-ol and (R)-1-cyclohexyl-2-propen-1-ol. Polysiloxanes containing racemic substituents were also prepared fron derivatives of racemic
Ätherspaltungen mit magnesium: ein direkter zugang zu allylmagnesium-phenolaten
作者:Adalbert Maercker
DOI:10.1016/s0022-328x(00)85393-0
日期:1969.8
Allyl phenyl ether and some of its derivatives are cleaved by metallic magnesium whereby allylmagnesium phenoxides are formed in excellent yields. Wurtztype coupling products, i.e. biallyl compounds, are only observed working in very concentrated solutions. The corresponding cleavage of 2H-chromene yields an interesting cyclic allylmagnesium phenoxide.
Nickel-catalyzed electrocarboxylation of allylic halides with CO<sub>2</sub>
作者:La-Xia Wu、Fang-Jie Deng、Lin Wu、Huan Wang、Tai-jie Chen、Ye-Bin Guan、Jia-Xing Lu
DOI:10.1039/d1nj02006d
日期:——
Nickel-catalyzed regioselective electrocarboxylation of allylic halides with CO2 at atmospheric pressure has been developed by adjusting reaction parameters, including catalyst, solvent, temperature and additive. β,γ-Unsaturatedcarboxylicacids were obtained in moderate to good yields and with high chain selectivity. This reaction shows tolerance to functional groups. In addition, cyclic voltammetry
通过调整包括催化剂、溶剂、温度和添加剂在内的反应参数,已开发出镍催化的烯丙基卤化物与 CO 2在大气压下的区域选择性电羧化反应。以中等至良好的产率和高链选择性获得了 β,γ-不饱和羧酸。该反应显示出对官能团的耐受性。此外,还进行了循环伏安法以提供镍催化的 CO 2烯丙基化的可能机制。