Synthesis, structure determination and immobilization of some dirhodium complexes with chiral binding thiolato ligands. Investigation of their catalytic activity for enantioselective hydrogenation

TY - JOUR

T1 - Synthesis, structure determination and immobilization of some dirhodium complexes with chiral binding thiolato ligands. Investigation of their catalytic activity for enantioselective hydrogenation

AU - Eisen, Moris

AU - Weitz, Pnina

AU - Shtelzer, Sarah

AU - Blum, Jochanan

AU - Schumann, Herbert

AU - Gorella, Boris

AU - Görlitz, Frank H.

PY - 1991/10/15

Y1 - 1991/10/15

N2 - (-)-cis[Dicarbonyl-μ-chloro-[μ-6,6-dimethylbicyclo[3.1.1]heptane-2-methanethiolato-S:S)]]bis[tris(1,1-dimethylethyl)phosphine]dirhodium (5a) and (+)-cis-[dicarbonyl-μ-chloro-[μ-5β-methyl-2α-(1-methyl-ethyl)cyclohexanethiolato-S:S]]bis[tris(1,1-dimethylethyl)phosphine]dirhodium (5b) were prepared from [Rh(CO)2]2(μ-Cl)2, P(t-Bu)3 and the corresponding sulfides (-)-cis-(myrtanethio)trimethylsilane (4a) and (+)-(neomenthanethio)trimethylsilane (4b). The molecular structures of 5a and 5b were determined by single-crystal X-ray diffraction (5a: C2221, a = 13.749(4), b = 23.509(9), c = 27.271(9) Å, Z = 8, R = 0.0443, Rw = 0.0491. 5b: P1, a = 16.209(6), b = 14.150(5), c=9.899(3) Å, Z = 2, R = 0.058, Rw = 0.094). Complex 5b was found to exist in the crystal as a pair of 1R,2R,5S- and 1S,2R,5S-epimers. Both chiral complexes have been immobilized by attachment to divinylbenzene-crosslinked polystyrene resins. Application of the chiral dirhodium complexes as catalysts for hydrogenation of methyl α-acetamidocinnamate revealed that while 5b leads to optically active N-acetylphenylalanine methyl ester (up to 50% ee) 5a gives only the racemic product. The immobilization of the complexes proved to improve the enantioselectivity of 5a but decreases the ability of 5b to induce asymmetric reduction.

AB - (-)-cis[Dicarbonyl-μ-chloro-[μ-6,6-dimethylbicyclo[3.1.1]heptane-2-methanethiolato-S:S)]]bis[tris(1,1-dimethylethyl)phosphine]dirhodium (5a) and (+)-cis-[dicarbonyl-μ-chloro-[μ-5β-methyl-2α-(1-methyl-ethyl)cyclohexanethiolato-S:S]]bis[tris(1,1-dimethylethyl)phosphine]dirhodium (5b) were prepared from [Rh(CO)2]2(μ-Cl)2, P(t-Bu)3 and the corresponding sulfides (-)-cis-(myrtanethio)trimethylsilane (4a) and (+)-(neomenthanethio)trimethylsilane (4b). The molecular structures of 5a and 5b were determined by single-crystal X-ray diffraction (5a: C2221, a = 13.749(4), b = 23.509(9), c = 27.271(9) Å, Z = 8, R = 0.0443, Rw = 0.0491. 5b: P1, a = 16.209(6), b = 14.150(5), c=9.899(3) Å, Z = 2, R = 0.058, Rw = 0.094). Complex 5b was found to exist in the crystal as a pair of 1R,2R,5S- and 1S,2R,5S-epimers. Both chiral complexes have been immobilized by attachment to divinylbenzene-crosslinked polystyrene resins. Application of the chiral dirhodium complexes as catalysts for hydrogenation of methyl α-acetamidocinnamate revealed that while 5b leads to optically active N-acetylphenylalanine methyl ester (up to 50% ee) 5a gives only the racemic product. The immobilization of the complexes proved to improve the enantioselectivity of 5a but decreases the ability of 5b to induce asymmetric reduction.

UR - http://www.scopus.com/inward/record.url?scp=0001566031&partnerID=8YFLogxK

U2 - 10.1016/S0020-1693(00)80368-0

DO - 10.1016/S0020-1693(00)80368-0

M3 - 文章

AN - SCOPUS:0001566031

SN - 0020-1693

VL - 188

SP - 167

EP - 176

JO - Inorganica Chimica Acta

JF - Inorganica Chimica Acta

IS - 2

ER -