Use of the Wilkinson Catalyst for the<i>ortho</i>-CH Heteroarylation of Aromatic Amines: Facile Access to Highly Extended π-Conjugated Heteroacenes for Organic Semiconductors
作者:Yumin Huang、Di Wu、Jingsheng Huang、Qiang Guo、Juan Li、Jingsong You
DOI:10.1002/anie.201406445
日期:2014.11.3
An unprecedented catalytic system composed of the Wilkinson catalyst [Rh(PPh3)3Cl] and CF3COOH enabled the highly regioselective cross‐coupling of aromatic amines with a variety of heteroarenes through dual CH bond cleavage. This protocol provided a facile and rapid route from readily available substrates to (2‐aminophenyl)heteroaryl compounds, which may be conveniently transformed into highly extended
pyrrolyl potassium afforded the corresponding derivatives. Their structures were characterised by NMR and HRMS, and some products were further characterised by X-ray crystal structure analysis. It was found that the locations of the hydrogen atoms within the two amidine fragments vary. The structures showed that in the phenylene-linked bis(amidinate)s, the hydrogen atoms were attached to different nitrogen
Synthesis of macrocyclic tetraamido compounds and new metal insertion process
申请人:——
公开号:US20040167329A1
公开(公告)日:2004-08-26
An improved method of synthesizing a macrocyclic tetraamido compound includes protecting the amino portion of an amino carboxylic acid to form a protected amino carboxylic acid; exposing the protected amino carboxylic acid to a first solvent, preferably a hydrocarbon solvent, such as toluene or 1,2-dichloroethane, dichloromethane, dibromomethane and 1,2-dibromoethane. The carboxylic acid portion of the protected amino carboxylic acid is then converted to an activated carboxylic acid by one of esterification or acid halide formation, to form a protected amino activated carboxylic acid derivative. The protected amino activated carboxylic acid derivative is reacted with a diamine in the presence of a second solvent, such as THF or ,2-dichloroethane, dichloromethane, dibromomethane and 1,2-dibromoethane, to form a protected diamide diamine intermediate. Following deprotection, the diamide diamine intermediate is reacted with an activated diacid, such as an activated malonate, oxalate or succinate derivative to form the macrocyclic tetraamido compound. The macrocyclic tetraamido compound may further be complexed with a transition metal.
Racemic N-aryl bis(amidines) and bis(amidinates): on the trail of enantioselective organolanthanide catalysts
作者:Michael S. Hill、Peter B. Hitchcock、Stephen M. Mansell
DOI:10.1039/b513521d
日期:——
A series of racemic N-aryl-substituted trans-1,2-diaminocyclohexyl (t-1,2-DACH)-linked bis(amidines) were synthesised and their solution behaviour, and solid-state structures were investigated. The amidine functionalities within these compounds were extremely sterically hindered, with ortho-aryl substitution found to hinder N–Ar bond rotation. The results of these studies were used to rationalise the lack of reactivity of these compounds with [YN(SiMe3)2}3]. Dilithiation of the t-1,2-DACH linked bis(amidines) did, however, proceed easily and the solution behaviour and solid-state structures of the resulting THF-solvated lithium amidinates were investigated. All the compounds showed similar structures in the solid-state, while NMR experiments indicated that the solid-state structures were likely to be maintained in solution. Attempted metathesis reactions with YCl3 did not, however, yield the desired yttrium chloride complexes.