Carbon-heteroatom coupling

Aromatic carbon-heteroatom coupling reactions with participation and formation of heterocycles 98JCS(P1)2615. 

V. Mechanisms for the Functionalization Sequence Carbon-Heteroatom Coupling to Release the Product... 

A. Five-Coordinate Intermediates Involved in Carbon-Heteroatom Coupling Reactions from Pt(TV)... 

Step growth reactions involving the homo- and heteropolycondensation of various bifunctional unsaturated monomers in the presence of transition metal-based coordination catalysts have appeared to be a very useful synthetic tool for the preparation of low and high molecular weight polymers with an unsaturation in the polymer backbone. These reactions lead to unsaturated hydrocarbon and non-hydrocarbon polymers where polymeric chains are formed by carbon-carbon and carbon-heteroatom coupling respectively. 

Transition metal-catalysed carbon-heteroatom coupling reactions primarily comprise the carbonylation polycondensation of dibromoarenes with aromatic diamines and bisphenols in the presence of carbon monoxide... 

Carbon-heteroatom coupling reactions including carbonylation and carboxy-lation polycondensations, promoted by transition metal catalysts, are becoming a promising route for various types of new condensation polymer. 

The general catalytic cycle for this carbonylation coupling reaction is analogous to direct carbon-heteroatom coupling [scheme (39)] except that carbon monoxide insertion takes place after the oxidative addition step and prior to the nucleophilic attack of the amine [scheme (40)] ... 

P. F. Engel and M. Pfeffer, Carbon-Carbon and Carbon-Heteroatom Coupling Reactions of Metallacarbynes, Chem. Rev., 1995, 95, 2281. 

The dihydride-dihydrogen complex OsH2(r]2-H2)(CO)(P Pr3)2 as a precursor for carbon-carbon and carbon-heteroatom coupling reactions... 

In recent years, it has been proved that complex 120 is a unique species with a completely different chemical behaviour than that of previously reported compounds [44]. Its reactions with diolefins, oximes, and cyclopentadienyl thallium give rise to interesting organometallic compounds containing organic fragments, which are activated to afford carbon-carbon and carbon-heteroatom coupling reactions. 

COXPiPr 3)2 AS A PRECURSOR FOR CARBON-CARBON AND CARBON-HETEROATOM COUPLING REACTIONS... 

In spite of the above mentioned limitations, it should be noted that a lot of carbon-carbon and carbon-heteroatom coupling reactions have been summarized in this review. These reactions have given rise to about 200 new compounds in recent years. Complexes 111, 115, and 116 containing an azetidine skeleton or the 1,3-thiazinyl derivatives 98-100 are of particular interest. In this respect, it should be mentioned that as a consequence of the discovery of the cephalosporins and the enormous development occurring in the chemistry of these antibiotics since the 1940s, the 1,3-thiazine nucleus has became one of the most important six-membered heterocycles [90]. 

Thus, in Part III, the Pd-catalyzed cross-coupUng including the carbon-carbon crosscoupling represented by the Negishi, StiUe, and Suzuki protocols as well as the Sono-gashira alkynylation (Sect. III.2) and the more recently developed carbon-heteroatom coupling reactions (Sect. III.3) are presented. In most of these reactions, reductive... 

Since this seminal report, numerous examples of C-C bond-forming reductive elimination from Pd complexes have been demonstrated [7-11]. In contrast, carbon-heteroatom bond-forming reactions from Pd species remain much rarer. This chapter presents a comprehensive review of the synthesis and reactivity of detectable Pd complexes that undergo carbon-heteroatom coupling. Furthermore, mechanistic aspects of these reductive elimination reactions are discussed in detail. 

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