Carbon-heteroatom coupling reactions

Triarylphosphine ligands are of utmost importance in transition-metal catalysis. Thus, direct palladium-catalysed high-speed generation of these ligands from secondary phosphines and aryl halide building blocks would be a suitable and convergent synthetic route with high flexibility. Stadler and Kappe have shown that this method for the 

The competitive formation of biphenyl as a minor byproduct can be readily accommodated in this mechanistic proposal. Guan has reported recently the related thiolation shown in Eq. (2.20), catalyzed by the closely related catalyst 48. However, a mechanistic study showed that the phosphinite pincer complex is not stable under the basic conditions and decomposes releasing KP(0)Me2 and PPhj. That 49 is not the actual catalyst of this reaction is supported by the fact that this is catalyzed more efficiently by a combination of Ni(cod)2 and HP(0)Me2 [71]. 

Szabo has developed C-X bond formahon reachons involving C-H bond achva-hon and Pd(II)/Pd(IV) cycles, using iodonium salts as oxidants. One of them is a 

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

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

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. 

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... 

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