Alkyne derivatives organometals

Linkers Synthesis and Structure of a Quasi-Planar Ptis Dendrimer Containing Five Clusters Connected by c-Alkynyl Spacers. Angew. Chem. Int. Ed., 42, 5990-5993. (d) Chin, C. S. Kim, M. Lee, H. Noh, S., and Ok, K. M. (2002). Regio- and Stereoselective C-C Bond Formation between Alkynes Synthesis of Linear Dienynes from Alkynes. Organometallics, 21, 4785-4793. (e) Bruce, M. I. Davy, J. Hall, B. C. van Galen, Y. Skelton, B. W., and White, A. H. (2002). Some Platinum(ll) Complexes Derived from Aromatie Alkynes. Appl. Organomet. Chem., 16, 559-568. 

The cyclic carbopalladation-cross-coupling tandem reaction has been extensively developed over the past several years. Despite earlier favorable findings with A1 and Zr [84], these metals are still scarcely used. On the other hand, organometals containing Sn and B have been widely used, and favorable results have been obtained for the formation of ffve-membered car-bocycles and heterocycles containing N and O from halodienes [88] (Eqs. 1 and 2 in Scheme 29), haloenynes [89-92] (Eqs. 3-5 in Scheme 29), haloaryl-alkynes [94,95] (Eqs. 6 and 7 in Scheme 29), and allenene derivatives [93,96] (Eqs. 8 and 9 in Scheme 29). 

Lactone derivatives with formulae Co2(CO)6(/i-CO)(RC2R COO), with the ligands bound to the metals only through a carbon atom, are obtained upon regioselective carbonylation of coordinated alkynes (a) G. Palyi, G. Varadi, A. Visi-Orosz and L. Marko, J. Organomet. 

To date, many electrophilic reagents, such as alkyl halides, alkenes, alkynes, carbonyl compounds, epoxides, alcohols, and ethers, have been investigated in AFC alkylation reactions. On the other hand, the reactive 5-membered heteroaromatic compounds, such as indole, pyrrole, furan, and thiophene derivatives, and electron-rich benzene derivatives have been successfully applied in AFC alkylation reactions. Indole and pyrrole derivatives are most popular substrates due to their high reactivity and account for almost 80% of the published methodologies. A variety of chiral organometal-lic catalysts and organocatalysts are employed in the catalytic AFC alkylation reactions with high enantiomeric control. 

M. L. H. Green and B. Jousseaume, J. Organomet. Chem., 1980,193, 339. Bis(isopropylcyclo-pentadienyl)tantalum chemistry. Some hydride, carbonyl, alkyl, alkyne, and phosphine derivatives, and an improved synthesis of niobocene dichloride. 

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