Six-Coordinate Ruthenium(II) Complexes Containing Unsymmetrical 1,2-Bis(phosphanyl)ethanes and 1-Arsanyl-2-phosphanylethanes as Ligands

Abstract

The bis(η3‐2‐methallyl)ruthenium(II) complexes [Ru(η3‐2‐MeC3H4)2(κ2‐Ph2PCH2CH2PR2)] [R = iPr (2), Cy (3)] were prepared from the cycloocta‐1,5‐diene derivative [Ru(η3‐2‐MeC3H4)2(η4‐C8H12)] (1) and the unsymmetrical 1,2‐bis(phosphanyl)ethanes Ph2PCH2CH2PR2. The As,P analogue [Ru(η3‐2‐MeC3H4)2(κ2‐Ph2PCH2CH2AstBu2)] (4) was obtained by the same route. The reaction of 2 with hexafluoroacetylacetone afforded the chelate compound [Ru(κ2‐[F6]acac)2(κ2‐iPr2PCH2CH2PPh2)], whereas treatment of 2 and 3 with pentachlorophenol gave the related, more labile complexes [Ru(κ2‐O,Cl‐OC6Cl5)2(κ2‐R2PCH2CH2PPh2)] [R = iPr (6), Cy (7)]. Preparation of the parent bis(acac) compound [Ru(κ2‐acac)2(κ2‐iPr2PCH2CH2PPh2)] (8), which could not be obtained from 2 and acacH, was achieved by ligand exchange of 6 and acetylacetone. The molecular structures of 2 and 6 were determined by X‐ray crystallography.

Geometric and Electronic Structure of aC1-Symmetric Ruthenium-Aryloxide Metathesis Catalyst: An Experimental and Computational Study

“…Alternatively, breaking the Ru···Br interaction in trans - 5a by constraining the Ru−O−C−C Ar dihedral angle to 90°, and reminimizing, restores the chelated structure. Precedents for this coordination mode are found in other o -haloaryloxide complexes, including Ru(κ 2 - O,Br -2,4,6-OC 6 H 2 Br 3 )(PPh 3 ) 2 (Ru−Br = 2.63 Å), Ru 3 (CO) 8 (κ 2 - O,Cl -OC 6 H 4 Cl) 2 , CpRu(κ 2 - O,Cl -OC 6 Cl 5 ), Ru(κ 2 - O,Cl -OC 6 Cl 5 ) 2 (κ 2 - P,P -Ph 2 PCH 2 CH 2 P i Pr 2 ), and Ru(κ 2 - S,F -SC 6 F 5 )(SC 6 F 5 )(PMe 2 Ph) 2 …”

A new route to achiral and chiral 1,2-bis(phosphino)ethanes, 1-arsino-2-phosphinoethanes, and 1,3-bis(phosphino)propanes and the molecular structure and catalytic activity of some rhodium(i) complexes derived thereof Dedicated to Professor Wolfdieter A. Schenk, a respected colleague and creative scientist, on the occasion of his 60th birthday.

“…4 After we prepared at the beginning of these studies a variety of rhodium(I) complexes with iPr 2 PCH 2 PR 2 (R = Ph, Cy) and iPr 2 PCH 2 AsR 2 (R = iPr, tBu) as ligands, 2,3 we later extended this work to corresponding ruthenium(II) compounds 5 and included, for comparison, also unsymmetrical 1,2-bis(phosphino)ethanes and 1-arsino-2-phosphinoethanes as coordinating units. 6,7 In the context of these studies we also observed that the stepwise reaction of [( 6 -p-cym)RuCl 2 ] 2 (cym = cymol) with Ph 2 PCH 2 CH 2 tPBu 2 and AgPF 6 leads to the formation of a hetero-tetranuclear Ru 2 Ag 2 compound in which the unsymmetrical bidentate ligand binds in a bridging mode. 6 Taking into consideration that rhodium complexes with optically active phosphine ligands are powerful tools not only in hydrogenation reactions but also in other parts of asymmetric organic synthesis, we decided to prepare a series of compounds [Rh( 4 -C 8 H 12 )(L-L)]PF 6 where L-L is an unsymmetrical and/or chiral bis(phosphino)methane, 1,2-bis(phosphino)ethane, 1-arsino-2-phosphinoethane or 1,3-bis(phosphino)propane.…”

“…Results for the hydrogenation of -acetamidocinnamic acid methylester (ACM) at 1 bar pressure of H 2 in iPrOH (entry[1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16] and in THF (entry[17][18][19][20][21][22][23][24][25][26][27][28][29][30][31][32] with complexes 12a-h as catalyst precursors a…”