- The 1,3-diaminobenzene-derived aminophosphine palladium pincer complex {C6H3[NHP(piperidinyl)2]2Pd(Cl)} - A highly active Suzuki-Miyaura catalyst with excellent functional group tolerance
-
The rapidly prepared 1,3-diaminobenzenederived aminophosphine pincer complex {C6H3 [NHP(piperidinyl)2] 2Pd(Cl)} (1) is an effective Suzuki catalyst with excellent functional group tolerance. Side-product formations, such as homocoupling, debromation or protodeboration have only rarely been detected and if so, were in all cases below the 5% level. The presented reaction protocol is universally applicable. Experimental observations indicate that palladium nanoparticles are the catalytically active form of 1.
- Bolliger, Jeanne L.,Frech, Christian M.
-
experimental part
p. 1075 - 1080
(2010/06/17)
-
- Dichloro-bis(aminophosphine) complexes of palladium: Highly convenient, reliable and extremely active suzuki-miyaura catalysts with excellent functional group tolerance
-
Dichloro-bis(aminophosphine) complexes are stable depot forms of palladium nanoparticles and have proved to be excellent SuzukiMiyaura catalysts. Simple modifications of the ligand (and/or the addition of water to the reaction mixture) have allowed their formation to be controlled. Dichlorobis[1- (dicyclohexylphosphany1)piperidine]palladium (3), the most active catalyst of the investigated systems, is a highly convenient, reliable, and extremely active Suzuki catalyst with excellent functional group tolerance that enables the quantitative coupling of a wide variety of activated, nonactivated, and deactivated and/or sterically hindered functionalized and heterocyclic aryl and benzyl bromides with only a slight excess (1.1-1.2 equiv) of arylboronic acid at 80°C in the presence of 0.2 mol % of the catalyst in technical grade toluene in flasks open to the air. Conversions of >95% were generally achieved within only a few minutes. The reaction protocol presented herein is universally applicable. Side-products have only rarely been detected. The catalytic activities of the aminophosphine-based systems were found to be dramatically improved compared with their phosphine analogue as a result of significantly faster palladium nanoparticle formation. The decomposition products of the catalysts are dicyclohexylphosphinate, cyclohexylphosphonate, and phosphate, which can easily be separated from the coupling products, a great advantage when compared with non-water-soluble phosphine-based systems.
- Bolliger, Jeanne L.,Frech, Christian M.
-
experimental part
p. 4075 - 4081
(2010/08/05)
-