名称:
Generation and Reactivity of {(Ethane-1,2-diyl)bis[diisopropylphosphine-κP]}-{[2,4,6-tri(tert-butyl)phenyl]phosphino-κP}rhodium ([Rh{PH(tBu3C6H2)}(iPr2PCH2CH2PiPr2)]): Catalytic C−P Bond Formationvia Intramolecular C−H/P−H Dehydrogenative Cross-Coupling
摘要:
The complex [Rh(eta (3)-benzyl)(dippe)] (1: dippe = bis(diisopropylphosphino)ethane = (ethane-1,2-diyl)bis-[diisopropylphosphine]) reacted cleanly with Mes*PH2 (2; Mes* = 2,4,6-'Bu3C6H2) to provide a new Rh species [Rh(H)(dippe)(L)] (3). L being the 2,3-dihydro-3-3-dimethyl-1H-phosphindole ligind4(= 'Bu2C6H2(CMe2CH2PH)) (Scheme 1). Complex 3 was converted to the corresponding chloride [Rh(Cl)(dippe)(L)] (6) when treated with CH2Cl2, whereas the dimeric species [Rh-2{mu-'Bu2C6H2(CMe2CH2P)}(mu -H)(dippe)(2)] (7) was formed upon thermolysis in toluene (Scheme 2). The structures of 6 and 7(.)C(7)H(8) were determined by X-ray crystallography. Complexes 1 and 3 served as catalyst precursors for the dehydrogenative coupling of C-H and P-H bonds in the conversion of 2 to 4 (Scheme 3). Deuteration studies with Mes* PD2 exposed a complex series of bond-activation pathways that appear to involve C-H activation of the dippe ligand by the Rh-atom (Schemes 4 and 5).
DOI:
10.1002/1522-2675(20011017)84:10<2958::aid-hlca2958>3.0.co;2-l