Mono‐ and Dinuclear Rhodium and Iridium Complexes with Chiral Phospholanes as Ligands

Observation of vinylidene emission in mixed phosphine/diimine complexes of Ru(II) at room temperature in solution

“…Complex l, nm ( 3 , mol À1 L cm À1 ) cis-[RuCl 2 (dcype) (bipy)] [35] 300(1.7 Â 10 À3 ); 354 (3.2 Â 10 À3 ); 490(3.0 Â 10 À3 ) cis-[RuCl 2 (PPh 3 ) 2 (bipy)] [34] 274 ( [39] 273(19.7 Â 10 À3 ); 311(7.4 Â 10 À3 ); 351(590); 468(68); 585 (38); 644 (37) sh ¼ shoulder, * 16-tmc ¼ tetramethyl-1,5,9,13-tetra-azacyclohexadecane. ligands show a metal-centered oxidation process around 1200 mV [38].…”

“…Despite the wide use of these complexes as precursors in a variety of organometallic synthesis and catalytic processes [18e28], their chemical and physical properties have not been systematically investigated. The vinylidene ruthenium(II) complexes are p systems containing the "M]C]C" unit, which can be used as a fragment for mono and polynuclear complexes and may find potential applications in functional materials [29e31], nonlinear optics [32], building blocks [13,18,33,34] and supramolecular photochemistry [35].…”

Regio- and Stereoselective Homodimerization of Monosubstituted Acetylenes in the Presence of the Second Generation Grubbs Catalyst

“…Many examples of effective run of the process in the presence of transition metal complexes have been described. Catalytic activity in the process has been reported to be shown by complexes of such metals as palladium [4,[7][8][9][10][11][12][13], rhodium [14][15][16][17][18][19], ruthenium [20][21][22][23][24][25][26][27][28][29], nickel [30], iridium [31][32][33], osmium [34,35], iron [36] and the f-block metals [37][38][39]. However, a highly selective synthesis of conjugated enynes by dimerization is still a challenging process.…”

ZnCl2‐Promoted Asymmetric Hydrogenation of β‐Secondary‐Amino Ketones Catalyzed by a P‐Chiral Rh–Bisphosphine Complex

“…The two minor signals are considered to be due to the chloridebridged binuclear rhodium complex (dimer in Scheme 1), which is less stable and has a higher catalytic activity. [10] When ZnCl 2 was added to the above solution, the signals attributable to the trimer almost vanished and the intensity of the signals corresponding to the dimer increased (Figure 2 c). In the HRMS spectra ( Figure S2), signals attributable to the dimer as [Rh 2 (m 2 -Cl) 2 (BenzP*) 2 ] + at m/z 840.0657 and its isotopic peaks and the signal for the monomer as [Rh-(BenzP*)] + at m/z 385.0622 were detected.…”

“…The dimer is less stable and more reactive and is directly converted into a solvated Rh I monomer or a Rh III monomer by the oxidative addition of hydrogen. [10] In doing so, the rhodium catalyst is reactivated to provide a higher turnover number.…”