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.
Triflic Acid Catalyzed 1,6-Conjugate Addition of Thiols to <i>p</i>
-Quinone Methides under Continuous-Flow Conditions
作者:Abhijeet S. Jadhav、Ramasamy Vijaya Anand
DOI:10.1002/ejoc.201700587
日期:2017.7.7
A simple and efficient protocol to access diarylmethyl thioethers through the triflicacidcatalyzed vinylogous Michael addition of aromatic and aliphatic thiols to p-quinone methidesundercontinuous-flowconditions by using a microreactor was developed.
B(C<sub>6</sub>F<sub>5</sub>)<sub>3</sub> catalysed 1,6-conjugate allylation of <i>para</i>-quinone methides: expedient access to allyl diarylmethanes
作者:Sriram Mahesh、Guddi Kant、Ramasamy Vijaya Anand
DOI:10.1039/c6ra19069c
日期:——
An efficient protocol for the synthesis of unsymmetrical allyl diarylmethanes through a Lewis acid catalysed 1,6-conjugate addition of allylsilanes to para-quinone methides is described.
<i>N</i>-Heterocyclic Carbene Catalyzed 1,6-Conjugate Addition of Me<sub>3</sub>Si-CN to <i>para</i>-Quinone Methides and Fuchsones: Access to α-Arylated Nitriles
N-heterocyclic carbene (NHC) as a catalyst is described. This protocol comprises an NHC catalyzed activation of Me3Si-CN followed by 1,6-conjugate addition of cyanide to para-quinone methides (p-QMs) and fuchsones leading to α-diaryl- and α-triaryl nitriles in good to excellent yields.
bis(amino)cyclopropenium ion has been investigated in conjugate additionreactions. The hydrogen atom, which is attached to the cyclopropene ring of bis(amino)cyclopropenium salts, is moderately acidic and can potentially serve as a hydrogen-bond donor catalyst in some organic transformations. This hypothesis has been successfully realized in the 1,6-conjugate additionreactions of p-quinone methides