Ruthenium complexes that incorporate a chiro-inositol derived diphosphinite ligand as catalysts for asymmetric hydrogenation reactions

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• 作者：Andrew Falshaw ; Graeme J. Gainsford ; Cornelis Lensink ; Angela T. Slade ; L. James Wright
• 关键词：Ruthenium ; Catalytic asymmetric hydrogenation of ketones ; chiro-Inositol ; Chiral diphosphinite ligand ; X-ray crystal structure
• 刊名：Polyhedron
• 出版年：2007
• 期刊代码：87_02775387
• 类别：ch
• 出版时间：22 January 2007
• 卷：26
• 期：2
• 页码：329-337
• 文件大小：240 K

摘要

The diol, 1d-1,2,5,6-tetra-O-methyl-chiro-inositol (D-9), can be conveniently prepared from 1d-chiro-inositol using a series of standard protection/deprotection steps. Treatment of D-9 with Phb>2b>PCl gives the chiral diphosphinite, 1d-3,4-bis(O-diphenylphosphino)-1,2,5,6-tetra-O-methyl-chiro-inositol (D-10). The structure of D-10 has been determined by X-ray crystallography. Using 1l-chiro-inositol as starting material and following the same synthetic sequence used to produce D-10, the other enantiomer of this diphosphinite, 1l-3,4-bis(O-diphenylphosphino)-1,2,5,6-tetra-O-methyl-chiro-inositol (L-10) can also be obtained. Ruthenium complexes of these diphosphinite ligands can be conveniently prepared through ligand substitution reactions with appropriate substrate complexes. Thus, treatment of [RuClb>2b>(COD)]b>nb> with D-10 in the presence of triethylamine produces the bis(diphosphinite) complex, RuHClb;ba;²(P,P)-1d-3,4-bis(O-diphenylphosphino)-1,2,5,6-tetra-O-methyl-chiro-inositol}b>2b> (11). In addition, reaction between RuClb>2b>(PPhb>3b>)b>3b>, D-10 and (1R,2R)-(+)-1,2-diphenylethylenediamine gives the mono(diphosphinite) complex, RuClb>2b>b;ba;²(P,P)-1d-3,4-bis(O-diphenylphosphino)-1,2,5,6-tetra-O-methyl-chiro-inositol}b;ba;²(N,N)-(1R,2R)-(+)-1,2-diphenylethylenediamine} (12). The closely related complex RuClb>2b>b;ba;²(P,P)-1d-3,4-bis(O-diphenylphosphino)-1,2,5,6-tetra-O-methyl-chiro-inositol}b;ba;²(N,N)-(1S,2S)-(−)-1,2-diphenylethylenediamine} (13) can be obtained in a similar manner using (1S,2S)-(−)-1,2-diphenylethylenediamine in place of the corresponding (+)-isomer. These new chiral, diphosphinite complexes catalyse the hydrogenation of the ketones acetophenone and 3-quinuclidinone to give the corresponding alcohols with low to moderate enantiomeric excesses. The complexes are not catalytically active for the hydrogenation of the olefin dimethylitaconate or the b1;-ketoester methyl benzoylformate.