Organometallic compounds carbon-metal couplings 293

Barbieri, G., Benassi, R., Taddei, F., Long-Range Proton-Metal and Carbon-Metal Coupling Constants in Organometallic Compounds. An Empirical Interpretation, Gazz. Chim. Ital. 105 [1975] 807/26. 

There are several recent texts dealing with NMR spectroscopy in general and the reader is referred to these texts for further information 117,135, 171,186, 214). The purpose of this review is to cover only the NMR spectroscopy of organometallic compounds, paying particular attention to the chemical shifts and coupling constants of carbon atoms directly attached to metals and metalloids. 

There have been a number of reports of indirect coupling constants to carbon in organometallic compounds (see Tables XXXI and XXXII). Several trends are discernible. For transition metal complexes, the trends in V(i3C—M—3ip) and (i C—M— H) appear to follow those observed for V( P—M— H) and V( P—M— P). For complexes of ruthenium, osmium, rhodium, iridium, palladium, and platinum, it is generally found that V(A—M—B) (A, B = P, H) is large when... 

Wrackmeyer, B., Carbon Carbon and Metal Carbon Indirect Nuclear Spin-Spin Coupling Constants J( C C) and J(M C) in Organometallic Compounds, Spectrosc. Intern. J. 1 [1982] 201/8. 

The Pd-catalyzed cross-coupling reactions of metal nucleophiles with carbon electrophiles are of considerable value for the regio- and stereocontrolled synthesis of functionalized organometallic compounds, in particular, silanes, stannanes, and boianes, which are important reagents for Pd-catalyzed carbon-carbon CTOss-coupling as shown in Sects. III.2.2-in.2.4. Symmetrical bimetallic compounds such as disilanes, distannanes, and diborons are usually used as metal nucleophiles. The present metallation is applicable to aryl, benzyl, vinyl, acyl, and allyl (Sect. V.2.3.3) electrophiles. 

The chemistry of fluorinated 1,3,5-triazines is not as well studied as the chemistry of their chloro derivatives. In case of fluorotriazines the reactions directed on the ring nitrogen atoms, displacement of fluorine atoms and reactions on carbon atoms on the ring with retention of the fluorine atoms appear to be the most characteristic ones. In this section the N-alkylation and N-acylation reactions, as well as replacement of fluorine atoms by a variety of nucleophiles will be considered. Metallation of fluorotriazines and synthesis on the basis of organometallic compounds, as well as the cross-coupling reactions were described. Also several examples of photochemical reactions and transformations are presented. 

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