摘要:
The present invention relates to a particularly economic overall method for producing menthol, specifically for producing optically active, essentially enantiomerically and diastereomerically pure L-menthol and racemic menthol, starting from the starting material citral which is available inexpensively on an industrial scale. The method comprises the following stepsa.1) catalytic hydrogenation of neral and/or geranial to give citronellal, b.1) cyclization of citronellal to isopulegol in the presence of an acidic catalyst, c.1) purification of isopulegol by crystallization and d.1) catalytic hydrogenation of isopulegol to give menthol.
摘要:
The present invention relates to a process for preparing optically active carbonyl compounds by asymmetrically hydrogenating α,β-unsaturated carbonyl compounds in the presence of optically active transition metal catalysts which are soluble in the reaction mixture and have at least one carbon monoxide ligand, the optically active catalyst which has at least one carbon monoxide ligand and is to be used in each case being prepared by pretreating a catalyst precursor with a gas mixture comprising carbon monoxide and hydrogen and the asymmetric hydrogenation being performed in the presence of carbon monoxide supplied additionally to the reaction mixture.
摘要:
The present invention relates to a particularly economic overall method for producing menthol, specifically for producing optically active, essentially enantiomerically and diastereomerically pure L-menthol and racemic menthol, starting from the starting material citral which is available inexpensively on an industrial scale. The method comprises the following steps a.1) catalytic hydrogenation of neral and/or geranial to give citronellal, b.1) cyclization of citronellal to isopulegol in the presence of an acidic catalyst, c.1) purification of isopulegol by crystallization and d.1) catalytic hydrogenation of isopulegol to give menthol.
摘要:
The present invention relates to a process for preparing optically active carbonyl compounds by asymmetrically hydrogenating α,β-unsaturated carbonyl compounds in the presence of optically active transition metal catalysts which are soluble in the reaction mixture and have at least one carbon monoxide ligand, the optically active catalyst which has at least one carbon monoxide ligand and is to be used in each case being prepared by pretreating a catalyst precursor with a gas mixture comprising carbon monoxide and hydrogen and the asymmetric hydrogenation being performed in the presence of carbon monoxide supplied additionally to the reaction mixture.
摘要:
The present invention relates to a particularly economic overall method for producing menthol, specifically for producing optically active, essentially enantiomerically and diastereomerically pure L-menthol and racemic menthol, starting from the starting material citral which is available inexpensively on an industrial scale. The method comprises the following stepsa) catalytic hydrogenation of neral and/or geranial to give citronellal,b) cyclization of citronellal to isopulegol in the presence of an acidic catalyst,c) purification of isopulegol by crystallization andd) catalytic hydrogenation of isopulegol to give menthol.
摘要:
The present invention relates to a process for preparing aldehydes by reacting an α,β-unsaturated carboxylic acid or a salt thereof with carbon monoxide and hydrogen in the presence of a catalyst comprising at least one complex of a metal of transition group VIII of the Periodic Table of the Elements with at least one compound of the formula (I), where Pn is pnicogen; W is a divalent bridging group having from 1 to 8 bridge atoms between the flanking bonds; R1 is a functional group capable of forming at least one intermolecular, noncovalent bond with the —X(═O)OH group of the compound of the formula (I); R2, R3 are each in each case optionally substituted alkyl, cycloalkyl, heterocycloalkyl, aryl or hetaryl or together with the pnicogen atom and together with the groups Y2 and Y3 if present form an optionally fused and optionally substituted 5- to 8-membered heterocycle; a, b and c are each 0 or 1; and Y1,2,3 are each, independently of one another, O, S, NRa or SiRbRc, where Ra,b,c are each H or in each case optionally substituted alkyl, cycloalkyl, heterocycloalkyl, aryl or hetaryl; and the use of the above-described catalyst for the decarboxylative hydroformylation of α,β-unsaturated carboxylic acids.
摘要翻译:本发明涉及一种通过使α-,β-不饱和羧酸或其盐与一氧化碳和氢气在催化剂存在下反应来制备醛的方法,所述催化剂包含至少一种式 具有式(I)的至少一种化合物的元素周期表,其中Pn是pnicogen; W是在侧翼键之间具有1至8个桥原子的二价桥连基团; R1是能够与式(I)化合物的-X(= O)OH基团形成至少一个分子间,非共价键的官能团; R2,R3各自为任选取代的烷基,环烷基,杂环烷基,芳基或杂芳基,或与pnicogen原子一起并与Y2和Y3基团一起形成任选稠合的和任选取代的5-至8-元杂环; a,b和c各自为0或1; 其中R a,b,c各自为H,或者在每种情况下均为任选取代的烷基,环烷基,杂环烷基,芳基或杂芳基;其中R 1和R 2各自独立地为O,S,NR a或SiR b R c。 以及使用上述催化剂进行α,β-不饱和羧酸的脱羧加氢甲酰化反应。
摘要:
The present invention relates to a process for the hydroformylation of compounds of the formula (I), where X is C, P(Rx), P(O—Rx) S or S(═O), where Rx is H, alkyl, cycloalkyl, heterocycloalkyl, aryl or hetaryl; A is a divalent bridging group having from 1 to 4 bridging atoms; and R1 is H, alkyl, alkenyl, alkynyl, cycloalkyl, heterocycloalkyl, aryl or hetaryl; or salts thereof; in which the compound of the formula (I) is reacted with carbon monoxide and hydrogen in the presence of a catalyst comprising a complex of a metal of transition group VIII with a compound of the formula (II), where Pn is a pnicogen atom; W is a divalent bridging group having from 1 to 8 bridging atoms; R2 is a functional group capable of forming an intermolecular, noncovalent bond with the group —X(═O)OH; R3, R4 are each alkyl, cycloalkyl, heterocycloalkyl, aryl or hetaryl; a, b, c are each 0 or 1; and Y1, Y2 and Y3 are each O, S, NRa or SiRbRc; and also compounds of the formula (II.a), where W′ is a divalent bridging group having from 1 to 5 bridging atoms between the flanking bonds, Z is O, S, S(═O), S(═O)2, N(RIX) or C(RIX)(RX); and RI to RX are each, independently of one another, H, halogen, nitro, cyano, amino, alkyl, etc.; or two radicals RI, RII, RIV, RVI, RVIII and RIX together represent the second part of a double bond.
摘要翻译:本发明涉及式(I)化合物加氢甲酰化的方法,其中X为C,P(Rx),P(O-Rx)S或S(= O)),其中Rx为H,烷基, 环烷基,杂环烷基,芳基或杂芳基; A是具有1至4个桥连原子的二价桥连基团; R 1为H,烷基,烯基,炔基,环烷基,杂环烷基,芳基或杂芳基; 或其盐; 其中式(I)的化合物与一氧化碳和氢气在包含过渡族VIII的金属与式(II)的化合物的络合物的存在下反应,其中Pn是酚醛原子; W是具有1至8个桥连原子的二价桥连基团; R2是能够与基团-X(= O)OH形成分子间,非共价键的官能团; R 3,R 4各自为烷基,环烷基,杂环烷基,芳基或杂芳基; a,b,c各自为0或1; Y1,Y2和Y3分别为O,S,NRa或SiRbRc; 以及式(II.a)化合物,其中W'是在侧翼键之间具有1至5个桥连原子的二价桥连基团,Z是O,S,S(= O),S(= O)2 ,N(RIX)或C(RIX)(RX); R 1和R 2各自独立地为H,卤素,硝基,氰基,氨基,烷基等; 或两个基团RI,RII,RIV,RVI,RVIII和RIX一起表示双键的第二部分。
摘要:
A process for preparing optically active 2-methylalkan-1-ol of the general formula (III) comprising the following steps: (i) carbonyl-selective reduction of 2-methylalk-2-en-1-al of the general formula (I) to 2-methylalk-2-en-1-ol of the general formula (II), (ii) enantioselective hydrogenation of 2-methylalk-2-en-1-ol to the general formula (iii), (iii) increasing the optical yield of the optically active 2-methylalkan-1-ol (III) obtained in step (ii) by a lipase-catalyzed acylation reaction, where the radical R means C1-C10-alkyl.
摘要:
The present invention relates to a process for asymmetric synthesis in the presence of a chiral catalyst comprising at least one complex of a metal of transition group VIII with ligands capable of dimerization via noncovalent bonds, such catalysts and their use.
摘要:
The invention relates to a process for preparing optically active alkylsuccinic acid monoalkyl esters of the formula (I) where D and E are independently of one another H, C1-C10 alkyl, R is C1-C10 alkyl, aryl or alkylaryl.