Regioselectivity ligand-controlled

Cabri, W., Candiani, L, Bedeschi, A. and Sand, R. (1992) PaUadium-catalyzed arylation of unsymmetrical olefins. Bidentate phoshine ligand controlled regioselectivity. J. Org. Chem., 57, 3558-63. 

Scheme 15.34 Ligand-controlled regioselective hydroboration of terminal alkynes.

Scheme 6.3 Arylation of indoles via CDC with ligand-controlled regioselectivity/...

Di Giuseppe A, Castarlenas R, Perez-TOTrente JJ, Crucianelli M, Polo V, Sancho R, Lahoz FJ, Oro LA (2012) Ligand-controlled regioselectivity in the hydrothiolation of alkynes by rhodium N-heterocyclic carbene catalysts. J Am Chem Soc 134(19) 8171-8183... 

For Heck reactions catalysed by Pd(OAc)2 associated with dppp, see Ref. [Ig] and (a) Cabri, W., Candiani, I. and Bedeshi, A. (1990) Ligand-controlled a-regioselectivity in palladium-catalyzed arylation of butyl vinyl ether. J. Org. Chem., 55, 3654-5 (b) Cabri, W., Candiani, L, De-Bernardinis, S. et al. (1991) Heck reaction on anthraquinone derivatives ligand, solvent, and salts effects. J. Org. Chem., 56, 5796-800 (c) Cabri, W., Candiani, L, Bedeshi, A. and Santi, R. (1991) Palladium-catalyzed a-arylation of vinyl butyl ether with aryl halides. Tetrahedron Lett., 32, 1753-6 (d) Cabri, W., Candiani, L, Bedeshi, A. et al. (1992) a-Regioselectivity in palladium-catalyzed arylation of acyclic enol ethers. J. Org. Chem., 57, 1481-6 (e) Cabri, W.,... 

The proper choice of the A-heterocyclic carbene (NHC) ligand in Ru-NHC complexes allowed the regioselective ligand-controlled hydrogenation of either the heterocyclic or the carbocyclic ring of a substituted quinoxaline in quantitative yields. 

The factors that control regioselectivity of palladium-catalyzed allylic substitutions have been the subject of numerous studies. Experiments that reveal the effects of both symmetric and unsymmetric ancillary ligands on this regioselectivity have been reported, along with experiments that have revealed effects of the type of nucleophile and the effects of basic additives. The following section describes some of this work on palladium-catalyzed processes. 

Scheme 2.34 Ligand-controlled, Ag-catalyzed regioselective amination of C(sp )-H bond [195]...

The presence of formates, oxalates, formic acid, and oxalic acid in the carbonylation of alkynes affects the regioselectivity. Also, the regioselectivity can be controlled to some extent by the proper selection of the ligands. A linear a,... 

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