1. Field of the Invention
The present invention relates to a novel ruthenium-iodo-optically active phosphine complex and a method for the production thereof and a method for the production of an optically active 4-methyl-2-oxetanone by using the ruthenium-iodo-optically active phosphine complex, and, particularly, to the above ruthenium-iodo-optically active phosphine complex used as a catalyst for a variety of organic synthetic reactions, especially, an asymmetric hydrogenation reaction, to a method for the production of the ruthenium-iodo-optically active phosphine complex and to a method for the production of an optically active 4-methyl-2-oxetanone which is useful as intermediates, such as raw materials for polymers, raw materials for synthesizing medicines and liquid crystal materials, which are used in organic synthetic chemical industries.
2. Description of Background Information
Many transition metal complexes have been used as the catalyst for organic synthetic reactions. In particular, metal complexes of a ruthenium metal and tertiary phosphine are well-known as the catalyst for asymmetric hydrogenation reactions. As ruthenium-optically active phosphine complex having, as a ligand, an optically active tertiary phosphine such as 2,2'-bis(diphenylphosphino)-1,1'-binaphthyl (hereinafter abbreviated as "BINAP"), the following compounds are known: EQU Ru.sub.x H.sub.y Cl.sub.z (tertiary phosphine).sub.2 (A).sub.p
wherein A represents a tertiary amine; when y is 0, x denotes 2, z denotes 4 and p denotes 1; when y is 1, x denotes 1, z denotes 1 and p denotes 0 (Japanese Patent Publication (JP-B) Nos. H4-81596 and H5-12354); EQU [RuH.sub.r (tertiary phosphine).sub.x ]T.sub.y
wherein T represents ClO.sub.4, BF.sub.4 or PF.sub.6 ; when r is 0, x denotes 1 and y denotes 2; when r is 1, x denotes 2 and y denotes 1 (JP-B Nos. H5-12353 and H5-12355); EQU [RuX.sub.a (Q).sub.b (tertiary phosphine)]Y.sub.c
wherein X represents a halogen atom; Q represents a benzene which may have a substituent or an acetonitrile; Y represents a halogen atom, ClO.sub.4, PF.sub.6, BPh4 (where Ph represents a phenyl group, the same as follows) or BF.sub.4 ; when Q is benzene which may have a substituent, a, b and c all represent 1; when Q is acetonitrile and a is 0, b denotes 4 and c denotes 2; when Q is acetonitrile and a is 1, b denotes 2 and c denotes 1. Incidentally, in the case where Q is p-cymene among benzene which may have a substituent and X and Y are iodine atoms, a, b and c all denote 1 or a, b and c may denote 1, 1 and 3 respectively (JP-B Nos. H7-57758 and H5-111639); EQU (tertiary phosphine).sub.w Ru(OCOR')(OCOR")
wherein R' and R" respectively represent a lower alkyl group, a halogenated lower alkyl group, a phenyl group which may have a lower alkyl substituent, .alpha.-aminoalkyl group or .alpha.-aminophenylalkyl group or R' and R" may be combined with each other to form an alkylene group, and w denotes 1 or 2 (JP-B Nos. H5-11119 and H5-12355); EQU RuJ.sub.2 (tertiary phosphine)
wherein J represents a chlorine atom, a bromine atom or an iodine atom (R. Noyori et al., J. Am. Chem. Soc., Vol. 109, No. 19, pp. 5856-5859 (1987)); and EQU RuG.sub.2 (tertiary phosphine)
wherein G represents an aryl group or a methacryl group (J. P. Genet et al., Tetrahedron: Asymmetry, Vol. 2, No. 7, pp. 555-567 (1991)). EQU Ru--I.sub.2 --(R.sup.1 -BINAP) (Kokai HEI 10-139791).
On the other hand, in JP-A No. H10-182678, a method for the production of SEGPHOS and ruthenium complexes containing this SEGPHOS as a ligand, specifically, [RuX(arene)(SEGPHOS)] (wherein X represents a halogen atom and arene represents a hydrocarbon having a benzene ring), Ru.sub.2 X.sub.4 (SEGPHOS).sub.2 NEt.sub.3 and Ru(methylallyl)2(SEGPHOS) are shown. Also, [Ru(BINAP)(CH.sub.3 CN).sub.4 ].sub.2.sup.+ X.sup.- (Y.sup.-) (wherein X represents a halogen atom and Y represents a halogen atom or BF.sub.4), [RuX(BINAP)(CH.sub.3 CN).sub.3 ].sup.+ X.sup.+, RuX.sub.2 (BINAP)(CH.sub.3 CN).sub.2 and the like which are similar to the complex of the present invention are shown by K. Mashima et al; J. Chem. Soc. Dalton Trans., pp. 2099-2107 (1992).
However, even if these ruthenium-optically phosphine complexes are used, there is the case where such a problem that only an insufficient catalytic activity and asymmetric yield are obtained depending on the objective reaction or on a reaction substrate is posed in actual industrialization.
While, 4-methyl-2-oxetanone (which is also called ".beta.-butyrolactone" or ".beta.-methyl-.beta.-propiolactone") has been used as raw materials for polymers or the like. Recently, the optically active materials of 4-methyl-2-oxetanone have been found to be useful and attracted considerable attention as described in Japanese Patent Application Laid-Open (JP-A) Nos. H6-256482, H6-329768, H7-53694, H8-53540 and H8-127645.
As the method for the production of optically active 4-methyl-2-oxetanone, the following methods are reported.
(a) A method in which 3-bromobutyric acid obtained by adding hydrobromic acid to crotonic acid is optically resolved using optically active naphthylethylamine and is then cyclized (J. Reid Shelton et al.; Polymer Letters, Vol. 9, pp. 173-178 (1971) and T. Sato et al; Tetrahedron Lett., Vol. 21, pp. 3377-3380 (1980)). PA1 (b) A method in which triethylorthoacetic acid is reacted with optically active 3-hydroxybutyric acid to obtain optically active 2-ethoxy-2,6-dimethyl-1,3-dioxane-4-one, which is then heat-decomposed (A. Griesbeck et al.; Helv. Chim. Acta, Vol. 70, pp. 1320-1325 (1987) and R. Breitschuh et al.; Chimia, Vol. 44, pp. 216-218 (1990)). PA1 (c) A method in which optically active 3-hydroxybutyric acid ester is reacted with methanesulfonyl chloride to mesylate a hydroxide group and the resulting ester is hydrolyzed, followed by condensation-cyclizing using sodium hydrogen carbonate (Y. Zhang et al.; Macromolecules, Vol. 23. pp. 3206-3212 (1990)). PA1 Furthermore, the following method is reported as an instance using the aforementioned ruthenium-optically active phosphine complex. PA1 (d) 4-Methylene-2-oxetanone (also called "diketene") is hydrogenated asymmetrically in an aprotic solvent such as a methylene chloride or tetrahydrofuran by using as a catalyst [RuCl[(S)-- or (R)-BINAP(benzene)]Cl or [Ru.sub.2 Cl.sub.4 [(S)-- or (R)-BINAP].sub.2 (NEt.sub.3) wherein Et represents an ethyl group (T. Ohta et al.; J. Chem. Soc., Chem. Commun., 1725 (1992)). PA1 (i) a carboxylate of the formula (4): EQU (T.sup.1).sub.a Z.sup.1 (4) PA1 (ii) a salt of the formula (5): EQU Z.sup.2.sub.b (T.sup.2).sub.c (5) PA1 (i) a carboxylate of the formula (4): EQU (T.sup.1).sub.a Z.sup.1 (4) PA1 (ii) a salt of the formula (5): EQU Z.sup.2.sub.b (T.sup.2).sub.c (5) PA1 an optically active tertiary phosphine (R.sup.1 -BINAP), in which R.sup.2 and R.sup.3 in the formula (2) are combined with each other to form a six-membered benzene ring and which is represented by the formula (7): ##STR2## wherein R.sup.1 represents an aryl group which may have a substituent selected from the group consisting of a lower alkyl group having 1 to 4 carbon atoms, a lower alkoxy group having 1 to 4 carbon atoms, a lower alkylamino group having 1 to 4 carbon atoms and a halogen atom, or a cycloalkyl group having 3 to 8 carbon atoms; PA1 an optically active tertiary phosphine (H.sup.8 --R.sup.1 -BINAP), in which R.sup.2 and R.sup.3 in the formula (2) are combined with each other to form a six-membered cyclohexyl ring and which is represented by the formula (8): ##STR3## wherein R.sup.1 is defined as indicated above in the formula (7), and; an optically active tertiary phosphine (R.sup.1 -SEGPHOS), in which R.sup.2 and R.sup.3 in the formula (2) are combined with each other to form a five-membered 1,3-dioxolan ring and which is represented by the formula (9): ##STR4## wherein R.sup.1 is defined as indicated above in the formula (7). PA1 (i) a complex of the formula (1): EQU [Ru--(I).sub.q --(T.sup.1).sub.n (SOL).sub.r (L)].sub.m (T.sup.2).sub.p (I).sub.s (1) PA1 (ii) a complex of the formula (1): EQU [Ru--(I).sub.q --(T.sup.1).sub.n (SOL).sub.r (L)].sub.m (T.sup.2).sub.p (I).sub.s (1) PA1 an optically active tertiary phosphine (R.sup.1 -BINAP), in which R.sup.2 and R.sup.3 in said formula (2) are combined with each other to form a six-membered benzene ring and which is represented by the formula (7): ##STR5## wherein R.sup.1 represents an aryl group which may have a substituent selected from the group consisting of a lower alkyl group having 1 to 4 carbon atoms, a lower alkoxy group having 1 to 4 carbon atoms, a lower alkylamino group having 1 to 4 carbon atoms and a halogen atom, or a cycloalkyl group having 3 to 8 carbon atoms; PA1 an optically active tertiary phosphine (H.sup.8 --R.sup.1 -BINAP), in which R.sup.2 and R.sup.3 in said formula 2 are combined with each other to form a six-membered cyclohexyl ring and which is represented by the formula (8): ##STR6## wherein R.sup.1 is defined as indicated above in said formula (7), and; an optically active tertiary phosphine (R.sup.1 -SEGPHOS), in which R.sup.2 and R.sup.3 in the formula (2) are combined with each other to form a five-membered 1,3-dioxolan ring and which is represented by the formula (9): ##STR7## wherein R.sup.1 is defined as indicated above in the formula (7); and, (iii) three different complexes of formulae (12), (13) and (14): EQU [Ru(R.sup.1 -SEGPHOS)(SOL).sub.4 ]I.sub.2 (12) EQU [Ru(R.sup.1 -SEGPHOS)(SOL).sub.4 ]I(anion) (13) EQU [RuI(R.sup.1 -SEGPHOS)(SOL).sub.3 ](anion) (14)
These methods however have the following problems. Specifically, in the method (a), a specific optically active amine is required as an optically resolving agent in an amount by mol equivalent to the raw material compound and unnecessary enantiomers are by-produced in an amount equivalent to the objective product. This method therefore involves much usefulness and is hence economically disadvantageous. In the methods (b) and (c), it is not easy to synthesize the raw material compound, specifically, optically active 3-hydroxybutyric acid or its ester. To mention in detail, it is necessary to heat-decompose optically active poly-3-hydroxybutyric acid ester produced by microorganisms or to form acetoacetic acid ester from 4-methylene-2-oxetanone by an alcoholysis reaction followed by asymmetric reduction. This method therefore involves many steps and is complicated. The method (d) succeeds in solving the aforementioned problems involved in the methods (a) to (c) but involves some problems; it has a low catalytic activity and requires long reaction time. Moreover, the optical purity of the resulting product produced in this method is as low as 70-92% e.e. This method has been improved as reported in JP-A No. H6-128245, H7-188201 and H7-206885. However, this method is not an industrially satisfactory method on account of its low catalytic activity.