[reaction: see text] A series of novel trans-ruthenium hydride borohydride complexes with chiral phosphinite and diamine ligands were synthesized. They can be used in the asymmetric transfer hydrogenation of aryl ketones, including base-sensitive ones, to give chiral alcohols in moderate to good enantioselectivities (up to 94% ee). They are also efficient catalysts for the Michael addition of malonates to enones with enantioselectivities of up to 90%. This kind of catalyst allows a one-pot tandem Michael addition/H(2) hydrogenation protocol to build structures with multiple chiral centers.

A method is reported for making a potentially very wide series of ruthenium hydrido chloro complexes with diamine and readily-prepared diphosphinite ligand modules as precatalysts for the asymmetric transfer hydrogenation of simple ketones to give chiral alcohols in good yield and enantioselectivity.Chiral alcohols are very important building blocks and synthetic intermediates in organic synthesis and the pharmaceutical industry.1,2 The reduction of prochiral ketones to give chiral alcohols is among the most fundamental subjects in modern synthetic chemistry. Noyori and co-workers provided an elegant solution for the asymmetric catalytic H 2 -hydrogenation of simple aryl ketones. Herein, we report the convenient, modular synthesis and characterization of complexes of the type transRuHCl(diphosphinite)(diamine) and their application in the asymmetric transfer hydrogenation of ketones. This approach allows the opportunity for rapid tuning of the catalyst structure due to the modular nature of the ligands and precatalysts.A wide variety of catalyst structures are readily constructed from three modules A-C. First BINOL (A, (R) or (S)) and diarylchlorophosphine (B, Ar 5 Ph or 3,5-Me 2 C 6 H 3 (xyl)) are combined to give the phosphinite ligand. Then this is reacted with RuHCl(PPh 3 ) 3 to produce an intermediate complex RuHCl(diphosphinite)(PPh 3 ) that is reacted in situ with a diamine C (in this case (R,R)-or (S,S)-DPEN) to produce the desired transRuHCl(diphosphinite)(diamine) complexes in yields of up to 88% (Scheme 1).The yellow solid product usually consists of two diastereomers in the ratio of 2:1 for 1 and 3 and 9:1 for 2 and only one for 4. Their structures depend on the placement of the trans hydride and chloride groups relative to the folded backbone of the diphosphinite ligand. The minor isomer slowly changes to the major isomer as the product crystallizes from solution over the course of two days. The major isomer also can partly isomerize to the minor isomer when it stays in solution for more than 24 h.The structure of 3 (Fig. 1){ is similar to that of transRuHCl((R)-BINAP)((R,R)-DPEN) 18a with the PPNN atoms in the equatorial plane of a slightly distorted octahedron and with the Ru-Cl bond leaning toward the NN side. The BINOP ligand is folded over the hydride ligand. Structure determinations of BINOP-like complexes are scarce but these also have folded diphosphinite ligands. 19A comparison of complexes 1-4 as precatalysts for the asymmetric transfer hydrogenation of acetophenone by 2-propanol in the presence of KO t

The synthesis, structural characterization, and magnetic behavior of a new 2D copper(II) compound with formula {[Cu2(mu-O2CMe)(mu-MedapO)(mu1,1-N3)2]n (CH3OH)n} 1, in which MedapOH is N-methyl-1,3-diamino-2-propanol is reported herein. 1 crystallizes in the triclinic system, space group P1, with unit cell parameters a = 6.688(5) A, b = 10.591(6) A, c = 12.100(7) A, alpha = 113.01(3) degrees, beta = 105.08(4) degrees, gamma = 93.93(3) degrees, Z = 2. The structure of 1 consists of neutral alternate 1D chains formed by the sequence of [Cu(1)-(mu1,1-N3)2-Cu(1)-(MedapO/acetate)-Cu(2)-(mu1,1-N3)2-Cu2)]. Each dinuclear [Cu(1)-Cu(2)] unit interacts with similar dinuclear units of neighbor chains in basis to large Cu-N(azido) distances to give a 2D arrangement. The magnetic behavior of 1 has been checked giving a net ferromagnetic coupling. The fit of the chiM versus T data as dinuclear compound affords a J value of 53.0 cm(-1) as a consequence of the orbital countercomplementarity phenomenon. The exchange pathways have been justified by density functional calculations.

An effective, modular catalytic system for the asymmetric transfer hydrogenation of acetophenone derivatives is developed. -(GUO, R.; ELPELT, C.; CHEN, X.; SONG, D.; MORRIS*, R. H.; Chem. Commun. (Cambridge) 2005, 24, 3050-3052; Dep. Chem., Univ. Toronto, Toronto, Ont. M5S 1A1, Can.; Eng.) -R. Staver 43-036