Reduction of carbonyl compounds via hydrosilylation. 3. Asymmetric reduction of keto esters via hydrosilylation catalyzed by a rhodium complex with chiral phosphine ligands
DIAMINE CROSSLINKING AGENTS, CROSSLINKED ACIDIC POLYSACCHARIDES AND MEDICAL MATERIALS
申请人:Seikagaku Corporation
公开号:US20170001948A1
公开(公告)日:2017-01-05
The invention provides a diamine crosslinking agent for acidic polysaccharides consisting of a diamine compound having a primary amino group at both terminals and an ester or thioester bond in the molecule, wherein the number of atom in the linear chain between at least one of the amino groups and the carbonyl carbon in the ester or thioester is 1 to 5; in particular, a diamine crosslinking agent for acidic polysaccharides which is represented by the general formula (I) below:
[the symbols in the formula are as described in the specification]; a crosslinked acidic polysaccharide obtained by forming crosslinks by amide bonding between the amino groups in the diamine crosslinking agent and carboxyl groups in an acidic polysaccharide; and a medical material including the crosslinked product.
Photodimerization of alkyl 2-naphthoates with chiral auxiliaries resulted in cubane-like anti head-to-head photodimers in 93% yield and with up to 59% diastereomeric excess. After removal of the chiral auxiliaries enantiomers of cubane-like photodimer of 2-naphthalene carboxylic acid were obtained in 80% yield.
METHOD FOR PRODUCING OPTICALLY ACTIVE 2-HYDROXY ESTER AND NOVEL INTERMEDIATE COMPOUND
申请人:Shiina Isamu
公开号:US20110319650A1
公开(公告)日:2011-12-29
Disclosed is a method for producing an optically active 2-hydroxy ester, comprising selectively esterifying one enantiomer of a racemic 2-hydroxy ester in a solvent containing a catalyst such as tetramisole or benzotetramisole, and a carboxylic acid anhydride, or a carboxylic acid anhydride and a carboxylic acid. In particular, in the case where the solvent contains a carboxylic acid anhydride, but does not contain a carboxylic acid, as the carboxylic acid anhydride, a carboxylic acid anhydride containing a tertiary or quaternary carbon atom in the a-position is used. On the other hand, in the case where the solvent contains a carboxylic acid anhydride and a carboxylic acid, as the carboxylic acid, a carboxylic acid containing a tertiary or quaternary carbon atom in the a-position is used.
Efficient Synthesis of Dimeric Oxazoles, Piperidines and Tetrahydroisoquinolines from <i>N</i>
-Substituted 2-Oxazolones
作者:Yun He、Piyush K. Agarwal、I. N. Chaithanya Kiran、Ruocheng Yu、Bei Cao、Cheng Zou、Xinghua Zhou、Huacheng Xu、Biao Xu、Lei Zhu、Yu Lan、K. C. Nicolaou
DOI:10.1002/chem.201601471
日期:2016.6.1
practical method for the construction of heterocycles from N‐substituted 2‐oxazolonesthrough cascade, BF3⋅Et2O/H2O‐catalyzed reactions involving iminium ion generation and trapping by external or internal olefinic and aryl moieties is described. Mechanistic and computational studies revealed the strong protic acid HBF4 as the initiating catalyst for these cascade reactions. Providing access to novel molecular
为杂环的来自建筑的温和和实用的方法Ñ通过级联取代-2-恶唑酮,BF 3 ⋅Et 2 ø/ H 2涉及亚胺离子产生和由外部或内部烯属的和芳基部分捕获O形催化的反应进行说明。机理和计算研究表明,强质子酸HBF 4是这些级联反应的引发催化剂。这些过程提供了获得新颖分子多样性的途径,可以促进化学生物学研究,药物发现工作和天然产物合成。
Facile alcoholysis of l-lactide catalysed by Group 1 and 2 metal complexes
Alkyl (S)-lactate and alkyl (S,S)-lactyllactate were rapidly and conveniently synthesized from L-lactide using Group1 and 2 metalcomplexes as catalyst in alcohol.