A method for esterification of one or more carboxylic acid groups in a compound containing one or more carboxylic acid groups wherein the esterification reagent is a diazo-compound of formula:

##STR00001##

wherein the R.sub.1 and R.sub.2 groups of the diazo compound are selected such that the corresponding organic compound of formula:

##STR00002##

exhibits a —C—H pKa value between 18 and 29 as measured in DMSO. Specific reagents and methods for esterification are provided. The esterification reagents provided exhibit high selectivity for esterification of carboxylic acid groups over reaction with amine, alcohol or thiol groups in the compound containing one or more carboxylic acid groups. The method can be used to selectively esterify carboxylic acid groups in peptides or proteins.

An object of the present invention is to enable the synthesis of various fluorine-containing compounds having an organic group at both terminals of their tetrafluoroethylene structure (—CF.sub.2—CF.sub.2—). The present invention provides a fluorine-containing complex compound including a fluorine-containing organic metal compound represented by formula (1a):
R.sup.1—CF.sub.2—CF.sub.2-M.sup.1  (1a)
wherein M.sup.1 is a metal selected from the group consisting of copper, zinc, nickel, iron, cobalt, and tin; and R.sup.1 represents an organic group, and at least one ligand selected from the group consisting of pyridine ring-containing compounds and phosphines.

An object of the present invention is to enable the synthesis of various fluorine-containing compounds having an organic group at both terminals of their tetrafluoroethylene structure (—CF.sub.2—CF.sub.2—). The present invention provides a fluorine-containing complex compound including a fluorine-containing organic metal compound represented by formula (1a):
R.sup.1—CF.sub.2—CF.sub.2-M.sup.1  (1a)
wherein M.sup.1 is a metal selected from the group consisting of copper, zinc, nickel, iron, cobalt, and tin; and R.sup.1 represents an organic group, and at least one ligand selected from the group consisting of pyridine ring-containing compounds and phosphines.

We provide a novel and useful process for preparing triphenyl-butene derivative. A process for the preparation of a compound represented by Formula (IV):

##STR00001##

wherein R.sup.1 is hydrogen or substituted or unsubstituted alkyl,
characterized by reacting a compound represented by Formula (V):

##STR00002##

with a compound represented by Formula (VI):

##STR00003##

wherein R.sup.1 has the same meaning as defined above,
in the presence of 1) a polyvalent metal chloride, 2) a reducing agent and 3) an alkali metal salt and/or a substituted or unsubstituted phenol.

We provide a novel and useful process for preparing triphenyl-butene derivative. A process for the preparation of a compound represented by Formula (IV):

##STR00001##

wherein R.sup.1 is hydrogen or substituted or unsubstituted alkyl,
characterized by reacting a compound represented by Formula (V):

##STR00002##

with a compound represented by Formula (VI):

##STR00003##

wherein R.sup.1 has the same meaning as defined above,
in the presence of 1) a polyvalent metal chloride, 2) a reducing agent and 3) an alkali metal salt and/or a substituted or unsubstituted phenol.

The present invention has an object to provide a compound which has excellent compatibility even with a cellulose ester resin having a low acetylation degree, is capable of providing an optical film having a high Rth value and high bleed resistance, and can be suitably used as a retardation enhancer; a cellulose ester resin composition including the compound; an optical film including the resin composition; and a liquid-crystal display device including the optical film. The present invention provides an epoxy ester compound represented by the following Formula (1) (in the formula, R.sup.1 to R.sup.4 each independently represent an alkyl group having 1 to 3 carbon atoms; and A's each represent an aromatic group (a1) or an aliphatic group (a2) having 1 to 4 carbon atoms, and the average presence ratio [(a1)/(a2)] of the aromatic groups (a1) to the aliphatic groups (a2) is 99.9/0.1 to 80/20 in terms of a molar ratio).

The present invention relates to novel Ruthenium complexes of formulae A1-A4 and their use, inter alia, for (1) dehydrogenative coupling of alcohols to esters; (2) hydrogenation of esters to alcohols (including hydrogenation of cyclic esters (lactones) or cyclic di-esters (di-lactones), or polyesters); (3) preparing amides from alcohols and amines—(including the preparation of polyamides (e.g., polypeptides) by reacting dialcohols and diamines and/or polymerization of amino alcohols and/or forming cyclic dipeptides from p-aminoalcohols; (4) hydrogenation of amides (including cyclic dipeptides, polypeptides and polyamides) to alcohols and amines; (5) hydrogenation of organic carbonates (including polycarbonates) to alcohols or hydrogenation of carbamates (including polycarbamates) or urea derivatives to alcohols and amines; (6) dehydrogenation of secondary alcohols to ketones; (7) amidation of esters (i.e., synthesis of amides from esters and amines); (8) acylation of alcohols using esters; (9) coupling of alcohols with water and a base to form carboxylic acids; and (10) preparation of amino acids or their salts by coupling of amino alcohols with water and a base. The present, invention further relates to the use of certain known Ruthenium complexes for the preparation of amino acids or their salts from amino alcohols.

The present invention relates to novel Ruthenium complexes of formulae A1-A4 and their use, inter alia, for (1) dehydrogenative coupling of alcohols to esters; (2) hydrogenation of esters to alcohols (including hydrogenation of cyclic esters (lactones) or cyclic di-esters (di-lactones), or polyesters); (3) preparing amides from alcohols and amines—(including the preparation of polyamides (e.g., polypeptides) by reacting dialcohols and diamines and/or polymerization of amino alcohols and/or forming cyclic dipeptides from p-aminoalcohols; (4) hydrogenation of amides (including cyclic dipeptides, polypeptides and polyamides) to alcohols and amines; (5) hydrogenation of organic carbonates (including polycarbonates) to alcohols or hydrogenation of carbamates (including polycarbamates) or urea derivatives to alcohols and amines; (6) dehydrogenation of secondary alcohols to ketones; (7) amidation of esters (i.e., synthesis of amides from esters and amines); (8) acylation of alcohols using esters; (9) coupling of alcohols with water and a base to form carboxylic acids; and (10) preparation of amino acids or their salts by coupling of amino alcohols with water and a base. The present, invention further relates to the use of certain known Ruthenium complexes for the preparation of amino acids or their salts from amino alcohols.

Provided is a catalyst for transesterification reactions, which contains an iron salen complex. Also provided is a method for producing an ester compound, which is characterized by carrying out a transesterification reaction between a starting material ester and a starting material alcohol with use of the catalyst.

Provided is a catalyst for transesterification reactions, which contains an iron salen complex. Also provided is a method for producing an ester compound, which is characterized by carrying out a transesterification reaction between a starting material ester and a starting material alcohol with use of the catalyst.