E -α-溴二苯乙烯在22°C下与Na [Re(CO)5 ]在THF中自发反应,生成Na [ReBr(CO)4 { Z -C(Ph)CHPh}]和Na [Re 2(CO)9 { Z -C( Ph)CHPh}]作为主要产品。Z -α-溴苯乙烯反应性较小,但产生的产物相同。该反应受到可见光或溶剂化电子源(NaK 2.8)的刺激,并可能受到喹啉基自由基陷阱的抑制。过量的Na [Re(CO)5 ]可以观察到Na [ReBr(CO)4 { Z -C(Ph)CHPh}]的初始形成及其完全转化为Na [Re 2(CO)9 { Z -C(Ph)CHPh}]。用CO处理Na [ReBr(CO)4 { Z -C(Ph)CHPh}]几乎将其定量转化为[Re(CO)5 { Z -C(Ph)CHPh}],其结构是通过单晶X射线衍射研究确定的。提出了用于该反应的自由基链机理,该机理包括以下步骤:(a)将Vin +自由基与Na
N-Heterocyclic carbene catalysed 1,6-hydrophosphonylation of p-quinone methides and fuchsones: an atom economical route to unsymmetrical diaryl- and triarylmethyl phosphonates
作者:Panjab Arde、Ramasamy Vijaya Anand
DOI:10.1039/c6ob00289g
日期:——
A convenient organocatalytic approach to access unsymmetrical diaryl- and triarylmethyl phosphonates using NHC as a Brønsted base catalyst is described. This atom-economical protocol enables the installation of phosphonate groups on p-quinone methides and fuchsones through a 1,6-conjugate addition of dialkylphosphites, and the corresponding phosphonates were obtained in excellent yields.
Uranyl-catalyzed hydrosilylation of <i>para</i>-quinone methides: access to diarylmethane derivatives
作者:Jipan Yu、Siyu Chen、Kang Liu、Liyong Yuan、Lei Mei、Zhifang Chai、Weiqun Shi
DOI:10.1039/d0ob02455d
日期:——
An efficient and convenient uranyl-catalyzed reductive hydrosilation reaction of para-quinone methides was developed by employing silane as the reductant.
B(C<sub>6</sub>F<sub>5</sub>)<sub>3</sub> catalysed reduction of para-quinone methides and fuchsones to access unsymmetrical diaryl- and triarylmethanes: elaboration to beclobrate
作者:Sriram Mahesh、Ramasamy Vijaya Anand
DOI:10.1039/c7ob02007d
日期:——
A mild and efficient method for the synthesis of unsymmetrical diaryl- and triarylmethanes through a B(C6F5)3 catalyzed reduction of para-quinone methides and fuchsones respectively, using the Hantzsch ester as a reducing source has been developed. Detailed mechanistic investigations revealed that the reaction actually proceeds through a Lewis acid–base pair complex derived from B(C6F5)3 and the Hantzsch
已开发出一种温和有效的方法,该方法通过使用Hantzsch酯作为还原源,通过B(C 6 F 5)3分别催化对苯醌甲基化物和丁二酮的还原反应,合成不对称的二芳基甲烷和三芳基甲烷。详细的机械研究表明,该反应实际上是通过衍生自B(C 6 F 5)3和汉茨(Hantzsch)酯的路易斯酸-碱对络合物进行的。
Accessing α-Arylated Nitriles via BF<sub>3</sub>·OEt<sub>2</sub> Catalyzed Cyanation of <i>para</i>-Quinone Methides Using <i>tert-</i>Butyl Isocyanide as a Cyanide Source
作者:Sachin R. Shirsath、Ganesh H. Shinde、Aslam C. Shaikh、M. Muthukrishnan
DOI:10.1021/acs.joc.8b01926
日期:2018.10.5
for the synthesis of α-diaryl and α-triaryl nitriles has been reported. This protocol allows α-diaryl- and α-triaryl nitriles to be accessed in good to excellent yields and with a broad substrate scope, which could be further functionalized to give a versatile set of products. This is the first example wherein tert-butyl isocyanide has been used as a cyanide source for the 1,6-conjugate addition.
Stable Carbocation Generated via 2,5-Cyclohexadien-1-one Protonation
作者:Craig Fraser、Rowan D. Young
DOI:10.1021/acs.joc.7b02668
日期:2018.1.5
Protonation of a substituted cyclohexadien-1-one (1) leads to the generation of carbocation [3]+, capable of effecting hydride abstraction and oxidation reactions. The molecular structure of [3]+ shows it to be structurally similar to [(p-MeO-C6H4)Ph2C]+. The ability to easily access [3]+ from stable and available precursors, such as 1 and commercially available acids, may allow a wider application