Rh-catalyzed addition of boronic acids to alkynes for the synthesis of trisubstituted alkenes in a biphasic system - Mechanistic study and recycling of the Rh/ m-TPPTC catalyst

• Published in: Journal of organometallic chemistry Vol. 689; no. 23; pp. 3820 - 3830
• Main Authors: Genin, Emilie, Michelet, Véronique, Genêt, Jean-Pierre
• Format: Journal Article
• Language: English
• Published: LAUSANNE Elsevier B.V 15.11.2004; Elsevier
• Subjects: Arylation of alkynes; Boronic acids; Chemistry; Chemistry, Inorganic & Nuclear; Chemistry, Organic; Homogeneous biphasic catalysis; Physical Sciences; Rhodium; Science & Technology; Water-soluble ligand; Homogeneous biphasic catalysis; Rhodium; Boronic acids; Water-soluble ligand; Arylation of alkynes; ASYMMETRIC 1,4-ADDITION; AQUEOUS-MEDIUM; BOND-FORMING REACTIONS; UNSATURATED SILANES; EFFICIENT SYNTHESIS; ALPHA,BETA-UNSATURATED CARBONYL-COMPOUNDS; ARYLBORONIC ACIDS; arylation of alkynes; CROSS-COUPLING REACTIONS; homogeneous biphasic catalysis; water-soluble ligand; METAL-COMPLEXES; boronic acids; rhodium; WATER
• ISSN: 0022-328X; 1872-8561
• DOI: 10.1016/j.jorganchem.2004.07.025

The use of [Rh(cod)OH] 2 associated with the water-soluble ligand m-TPPTC is highly efficient for the preparation of trisubstituted alkenes via arylation of alkynes. Aryl, heteroaryl, silylated and alkyl substituted alkynes reacted equally well with various boronic acids, leading regioselectively to functionalized alkenyl derivatives in high yields. The efficient recycling of the system and the mechanism are disclosed. The versatile preparation of trisubstituted alkenes via selective Rh-catalyzed arylation of alkynes is described in water and in a water/toluene biphasic system. For hydrophobic alkyl alkynes, the reaction afforded either alkenes or dienes depending on the temperature and the solvent conditions. Aryl, heteroaryl, silylated and alkyl substituted alkynes reacted equally well with various boronic acids, leading regioselectively to functionalized alkenyl derivatives in high yields (65–99%). The mechanism was investigated in toluene/water mixture or water and involves a vinylrhodium complex. The efficient recycling of the Rh/ m-TPPTC system is disclosed with excellent yield (92–96%) and purity of the alkene.