Palladate Precatalysts for the Formation of C–N and C–C Bonds

Abstract

A series of imidazolium-based palladate precatalysts has been synthesized and the catalytic activity of these air- and moisture-stable complexes evaluated as a function of the nature of the imidazolium counterion. These precatalysts can be converted under catalytic conditions to Pd-NHC species capable of enabling the Buchwald–Hartwig aryl amination and the α-arylation of ketones. Both reactions can be carried out efficiently under very mild operating conditions. The effectiveness of the protocol was tested on functionality-laden substrates.

N-Heterocyclic carbene complexes enabling the α-arylation of carbonyl compounds

“…4). 37 These complexes can be easily synthesized by the simple addition of an azolium salt to the dimeric palladium precursor of interest ([Pd(m-Cl)(Z 3 -allyl)] 2 or [Pd(m-Cl)(Z 3 -cinnamyl)] 2 ). All tested complexes 19-24 showed high catalytic activity (conversion: 94-99%) in the reaction of propiophenone with 4-chlorotoluene (Scheme 16).…”

“…All tested complexes 19-24 showed high catalytic activity (conversion: 94-99%) in the reaction of propiophenone with 4-chlorotoluene (Scheme 16). 37 The arylation was carried out under air, using non-anhydrous solvents and at low catalyst loading (0.2 mol%). Gratifyingly, the sterically hindered aryl chlorides were successfully coupled with the more challenging a-tetralone and acetophenone (Scheme 17).…”

“…In 2014, Peris and colleagues prepared a series of Ni-NHC complexes with three different types of NHC ligands: imidazolylidenes, benzimidazolylidenes and pyrene-imidazolylidenes (35)(36)(37). They evaluated the catalytic activity of the synthesized nickel complexes (Fig.…”

Anticancer Indole-Based Chalcones: A Structural and Theoretical Analysis

“…(E)-3-(4-Bromophenyl)-1-(1-ethyl-1H-indol-3-yl)prop-2-en-1-one (3a) [22,23]. Yield 1.75 g (4.95 mmol, 93%); m.p.…”

Synthesis and catalytic activity of palladium complexes bearing N-heterocyclic carbenes (NHCs) and 1,4,7-triaza-9-phosphatricyclo[5.3.2.1]tridecane (CAP) ligands

“…Analytical data match those reported in the literature. 24 4-(Anthracen-9-yl)morpholine (6c). The compound was synthesized according to general procedure from 9-chloroanthracene ( 213 Analytical data match those reported in the literature.…”