摘要:
Phospholanes and diphospholanes of the formula I ##STR1## where: R.sup.1 and R.sup.2 are, independently of one another, C.sub.1 -C.sub.6 -alkyl, aryl, alkylaryl,R.sup.1 is also hydrogen,A is either R.sup.1 or ##STR2## B is a linker having 1-5 carbon atoms between the two phosphorus atoms, and their use as catalyst in asymmetric synthesis.
摘要:
The invention relates to a process for preparing substituted chroman derivatives of the general formula VII, ##STR1## where X is the group --CN, --COOR.sup.3, --CHO, --CH.sub.2 OR.sup.7 or --CH(OR.sup.8).sub.2,R.sup.2 is a C.sub.1 -C.sub.23 -alkyl, C.sub.2 -C.sub.23 -alkenyl, C.sub.6 -C.sub.18 -aryl or C.sub.7 -C.sub.18 -aralkyl radical,R.sup.3 is hydrogen or an optionally substituted C.sub.1 -C.sub.4 -alkyl radical,R.sup.4, R.sup.5, R.sup.6 are, independently of one another, hydrogen or a C.sub.1 -C.sub.4 -alkyl radical,R.sup.7 is hydrogen or a C.sub.1 -C.sub.4 -alkyl radical,R.sup.8 is a C.sub.1 -C.sub.4 -alkyl radical, or the two radicals are a C.sub.2 -C.sub.6 -alkylene radical which links the two oxygen atoms to form a cyclic acetal and is optionally branched or may carry one or two carboxyl groups, cyclohexyl or phenyl radicals,and to the novel intermediates of the process.
摘要:
The invention relates to a lipase variant which can be prepared by carrying out, on the amino acid sequence of a starting lipase selected from the lipase homologous family I.1 or I.2, at least one amino acid substitution in those positions which correspond to the positions 17, 29, 30, 52, 86, 117, 122, 160, 163, 167, 265, 266, 286, 289 in the prototype lipase sequence SEQ ID NO: 1.
摘要翻译:本发明涉及脂酶变体,其可通过在选自脂肪酶同源家族I.1或I.2的起始脂肪酶的氨基酸序列上进行至少一个氨基酸取代而制备, 原型脂肪酶序列SEQ ID NO:1中的位置17,29,30,25,66,117,122,160,163,167,265,266,286,289。
摘要:
In a process for converting the achiral meso form or the racemate of an ansa-metallocene complex or a mixture thereof into one of its enantiomers, the conversion is carried out photochemically in the presence of an enantiomerically pure auxiliary reagent.
摘要:
The invention relates to a method for producing the optically active alkanols of formula (I), wherein n is an integer of from 0 to 5; Cyc represents an optionally substituted, mononuclear or polynuclear, saturated or unsaturated, carbocylic or heterocyclic ring, and R1 represents halogen, SH, OH, NO2, NR2R3 or NR2R3R4+X−, wherein R2, R3 and R4 independently represent H or a lower alkyl or lower alkoxy group and X− represents a counterion. According to the invention, an enzyme (E) selected from the groups of dehydrogenases, aldehyde reductases and carbonyl reductases is incubated in a medium containing the alkanone of formula (II), wherein n, Cyc and R1 are defined as above, in the presence of reduction equivalents. The compound of formula (II) is enzymatically reduced to the compound of formula (I) and the reduction equivalents consumed during reaction are regenerated by reacting a sacrificial alcohol to the corresponding sacrificial ketone using enzyme (E) and at least partially removing the sacrificial ketone from the reaction medium, and then isolating the product (I) so produced.
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 the preparation of enantiomerically pure (S)-3-methyl-amino-1-(thien-2-yl)propan-1-ol of the formula II-S by obtainment of (S)-3-hydroxy-3-thien-2-ylpropio-nitrile from its enantiomer mixture with the R isomer and the subsequent reaction of (S)-3-hydroxy-3-thien-2-ylpropionitrile with hydrogen and methylamine in the presence of a catalyst to give II-S.
摘要:
A catalyst system containing as active constituentsA) metal complexes of the formula I ##STR1## wherein the substituents have the meanings set forth in the specification andB) a compound capable of forming metallocenium ions.
摘要:
Optically active phosphines of the general formula I or II ##STR1## where the variables have the following meanings: X is an optically active terpene radical, R is an unsubstituted or substituted phenyl radical, Y is a bridge member having 1-10 C atoms in the formula I n is 1,2 or 3 and m is 0,1 or 2 with the proviso that n+m=3 in the formula II n is 1 or 2 and m is 0 or 1 with the proviso that n+m=2, their preparation and use are described.
摘要翻译:通式I或II的光活性膦XnPRm I u> II其中变量具有以下含义:X是光学活性萜烯基,R是未取代或取代的苯基,Y是具有1-10个 式I中的C原子是1,2或3,m是0,1或2,条件是式II中n + m = 3是1或2,m是0或1,条件是n + m = 2,描述了它们的制备和用途。
摘要:
A method for racemizing optically active secondary alcohols by incubating these alcohols with at least one alcohol dehydrogenase of the E.C. 1.1.1. class.