Biaryl P,N ligand

Very recently, an imidazole-based chiral biaryl P,N-ligand 96 (Fig. 3.1) has been developed and applied in the enantioselective A -coupling reaction [135]. The incorporation... 

F. S. P. Cardoso, K. A. Abboud, A. Aponick, J. Am. Chem. Soc. 2013, 135, 14548-14551. Design, preparation, and implementation of an imidazole-based ehiral biaryl P,N-ligand for asymmetric catalysis. 

Kndpfel, T. R, Aschwanden, P, Ichikawa, T., Watanabe, T., Carreira, E. M. (2004). Readily available biaryl P,N ligands for asymmetric catalysis. Angewandte Chemie International Edition, 43, 5971-5973. 

Aryltrialkoxy- and diaryldialkoxytitaniums are relatively stable (some of them are even distillable) compounds which readily undergo palladium-catalysed reaction with aryl iodides, bromides and chlorides, as well as triflates to furnish the biaryls in very high yields. For instance, the reaction of 2-naphthyl triflate (165) with phenyltitanium triisopropoxide (212, in 20 mol% excess) catalysed by palladium-complex of N,P-bidentate ligand 213 gave 2-phenylnaphthalene (214) in 98% yield [143], respectively, Scheme 40. 

Ru/diphosphine/diamine were shown by Noyori (For a recent account see [87]) to be effective hydrogenation catalysts of ketones without a- or (3-functionality. The absolute configurations of the P P and N N ligands have to be matched. The technology has been licensed by several companies using various biaryl diphosphines but it is not clear whether it is already used for concrete manufacturing purposes. 

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