Triazine-wingtips accelerated NHC-Pd catalysed carbonylative Sonogashira cross-coupling reaction
Kan Zhang1, Yanxiu Yao1, Wenjin Sun1
1Key Laboratory of Applied Surface and Colloid Chemistry, Xi'an Key Laboratory of Organometallic Material Chemistry, School of Chemistry and Chemical Engineering, Shaanxi Normal University, Xi'an, 710119, P. R. China. zwgao@snnu.edu.cn.
Abstract:
The transmetalation as the rate-limiting step was effectively accelerated by newly designed N-heterocyclic carbenes with triazine wingtips (T-NHC). By using a ppm-level precatalyst T-NHC-Pd (8), the highly efficient coupling of aryl iodide, alkyne and carbon monoxide furnished a variety of ynone compounds. T-NHC-Pd (5), which deprotonated 4-methyl-phenylacetylene under mild conditions, converted into alkynyl-coordinated catalytic active species PdCl(T-NHC)(Py)(alkynyl). In the putative Pd/Pd catalytic cycle, both triazine-wingtips and NHCs are key players for establishing the carbonylative cross-couplings with high TON and TOF.
More Related Videos
19:58Palladium N-Heterocyclic Carbene Complexes: Synthesis from Benzimidazolium Salts and Catalytic Activity in Carbon-carbon Bond-forming Reactions
Published on: July 30, 2017
07:50Efficient Synthesis of All-Carbon Quaternary Centers via the Conjugate Addition of Functionalized Monoorganozinc Bromides
Published on: May 26, 2019
Related Concept Videos
Diazonium Group Substitution with Halogens and Cyanide: Sandmeyer and Schiemann Reactions
Nucleophilic Aromatic Substitution of Aryldiazonium Salts: Aromatic SN1
In the Sandmeyer reaction, for example, the diazonio group is replaced by a chloro, bromo,...
Aldehydes and Ketones to Alkenes: Wittig Reaction Mechanism
The reaction begins with the nucleophilic addition between a phosphorus ylide and the carbonyl compound. Due to its carbanionic character, phosphorus ylide acts as a strong nucleophile and attacks the electrophilic carbonyl group. This generates a charge-separated dipolar intermediate called betaine. The negatively charged oxygen atom and...
[4+2] Cycloaddition of Conjugated Dienes: Diels–Alder Reaction
β-Dicarbonyl Compounds via Crossed Claisen Condensations
Cycloaddition Reactions: Overview
![Mizoroki-Heck Cross-coupling Reactions Catalyzed by Dichloro{bis[1,1',1''-phosphinetriyltripiperidine]}palladium Under Mild Reaction Conditions](/_next/image?url=https%3A%2F%2Fcloudfront.jove.com%2FCDNSource%2Fteasers%2F51444.jpg&w=3840&q=50)