Organometallic carbon metal couplings

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. 

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. 

Carbon monoxide, a common ligand in organometallic chemistry, is known to insert into palladium-carbon bonds readily. This feature of the metal is frequently utilized when palladium catalyzed reactions are run in the presence of CO. The products of such reactions, also known as carbonylative couplings, incorporate a carbonyl group between the coupling partners. 

Reactions other than Lewis acid-base associations/dissociations are frequently observed wit donor molecules, leading notably to solvolysis, oxygen or sulfur abstraction, insertion reaction and carbon-carbon coupling reactions. The tendency to form metal-element multiple bonds i remarkable in this respect the activation of dinitrogen by tantalum or niobium is unique. Th formation and chemistry of constrained reactive metallacycles open another promisin fast-developing area, on the frontier with organometallic chemistry. 

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