摘要:
Optically active cyanohydrins are prepared by addition of hydrogen cyanide to aldehydes in the presence of catalysts which comprise the dipeptide derivative represented by the formula ##STR1## wherein R.sup.1 represents an isopropyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, a methyl group, a benzyl group or a phenyl group, R.sup.2 represents a benzyl group, an indol-3-ylmethyl group, an isopropyl group, an isobutyl group or a phenyl group, R.sup.3 represents a lower alkoxy group, a hydroxy group or a mono- or di-lower alkylamino group, R.sup.4 represents a hydrogen atom, or R.sup.2 and R.sup.4 are bonded together at their terminals to form a CH.sub.2 CH.sub.2 CH.sub.2 group, R.sup.5, R.sup.6, R.sup.7 and R.sup.8 are the same or different, and each represents a hydrogen atom, a halogen atom, a lower alkyl group or a lower alkoxy group or R.sup.5 and R.sup.6, R.sup.6 and R.sup.7, or R.sup.7 and R.sup.8 are bonded together at their terminals to form CH.dbd.CH--CH.dbd.CH or OCH.sub.2 O, and * denotes an absolute configuration of S or R, and a titanium (IV) alkoxide.
摘要:
A preparation process for a cyclic conjugated polymer, includes the steps of deprotonating a monohalogenated cyclic conjugated compound of a 5- to 7-membered ring using a deprotonation catalyst comprising secondary amine represented by R1NHR2 (R1 and R2 are the same or different and are each a branched or cyclic alkyl group of 1 to 15 carbon atoms or a phenyl group) and a Grignard reagent represented by R3MgX (X is a halogen atom selected from chlorine, bromine and iodine, and R3 is a straight-chain or branched alkyl group of 1 to 6 carbon atoms) and polymerizing the deprotonated monohalogenated cyclic conjugated compound.
摘要:
(S)-cyanohydrins are produced by asymmetric addition of hydrogen cyanide to aldehydes in the presence of a catalyst of cyclo-[(S)-leucyl-(S)-histidyl].
摘要:
A catalyst for asymmetric induction is provided which comprises an amino acid amide derivative represented by the formula [I]: ##STR1## wherein R.sup.1 represents an isopropyl group, etc., R.sup.2 and R.sup.3 are the same or different and each represents a lower alkyl group, etc., R.sup.4 represents a chlorine atom, etc., R.sup.5, R.sup.6 and R.sup.7 are the same or different and each represents a hydrogen atom, etc., and * denotes an abosolute configuration of S or R, and a titanium (IV) alkoxide.Optically active cyanohydrins are obtained in high yield and at high purity by addition of hydrogen cyanide to aldehyde compounds in the presence of the above mentioned catalyst.
摘要:
A preparation process for a cyclic conjugated polymer, includes the steps of deprotonating a monohalogenated cyclic conjugated compound of a 5- to 7-membered ring using a deprotonation catalyst comprising secondary amine represented by R1NHR2 (R1 and R2 are the same or different and are each a branched or cyclic alkyl group of 1 to 15 carbon atoms or a phenyl group) and a Grignard reagent represented by R3MgX (X is a halogen atom selected from chlorine, bromine and iodine, and R3 is a straight-chain or branched alkyl group of 1 to 6 carbon atoms) and polymerizing the deprotonated monohalogenated cyclic conjugated compound.