Chiral Ion-Pair Organocatalyst-Promoted Efficient Enantio-selective Reduction of α-Hydroxy Ketones
作者:Yiliang Zhang、Li He、Lei Shi
DOI:10.1002/adsc.201800053
日期:2018.5.16
The enantioselective reduction of α‐hydroxy ketones with catecholborane has been developed employing 5 mol% of an 1,1′‐bi‐2‐naphthol (BINOL)‐derived ion‐pair organocatalyst. This methodology provides a straightforwardaccess to the corresponding aromatic 1,2‐diols in high yields (up to 90%) with excellent enantioselectivities (up to 97%). Furthermore, the α‐amino ketones also could be reduced with
Structurally Defined Molecular Hypervalent Iodine Catalysts for Intermolecular Enantioselective Reactions
作者:Stefan Haubenreisser、Thorsten H. Wöste、Claudio Martínez、Kazuaki Ishihara、Kilian Muñiz
DOI:10.1002/anie.201507180
日期:2016.1.4
Molecular structures of the most prominent chiral non‐racemic hypervalent iodine(III) reagents to date have been elucidated for the first time. The formation of a chirally induced supramolecular scaffold based on a selective hydrogen‐bonding arrangement provides an explanation for the consistently high asymmetric induction with these reagents. As an exploratory example, their scope as chiral catalysts
Highly Enantioselective Iron-Catalyzed <i>cis</i>
-Dihydroxylation of Alkenes with Hydrogen Peroxide Oxidant via an Fe<sup>III</sup>
-OOH Reactive Intermediate
作者:Chao Zang、Yungen Liu、Zhen-Jiang Xu、Chun-Wai Tse、Xiangguo Guan、Jinhu Wei、Jie-Sheng Huang、Chi-Ming Che
DOI:10.1002/anie.201603410
日期:2016.8.22
catalysts for highly enantioselective asymmetric cis‐dihydroxylation (AD) of alkenes with broad substrate scope remains a challenge. By employing [FeII(L)(OTf)2] (L=N,N′‐dimethyl‐N,N′‐bis(2‐methyl‐8‐quinolyl)‐cyclohexane‐1,2‐diamine) as a catalyst, cis‐diols in up to 99.8 % ee with 85 % isolated yield have been achieved in AD of alkenes with H2O2 as an oxidant and alkenes in a limiting amount. This “[FeII(L)(OTf)2]+H2O2”
开发具有良好底物范围的烯烃的高对映选择性不对称顺二羟基化(AD)的环境友好型催化剂仍然是一个挑战。通过使用[Fe II(L)(OTf)2 ](L = N,N'-二甲基-N,N'-双(2-甲基-8-喹啉基)-环己烷-1,2-二胺)作为催化剂,在以H 2 O 2为氧化剂的烯烃和数量有限的烯烃的AD中,已实现了高达99.8%ee的顺式二醇和85%的分离产率。该“ [Fe II(L)(OTf)2 ] + H 2 O 2”方法适用于(E)-烯烃和末端烯烃(24个实例,ee大于80%,最大1 g)。机理研究包括18种O-标记,UV / Vis,EPR,ESI-MS分析和DFT计算,为手性Fe III- OOH活性物种参与两个C-O键的对映选择性形成提供了证据。
Enantioselective trans-Dihydroxylation of Aryl Olefins by Cascade Biocatalysis with Recombinant <i>Escherichia coli</i> Coexpressing Monooxygenase and Epoxide Hydrolase
作者:Shuke Wu、Yongzheng Chen、Yi Xu、Aitao Li、Qisong Xu、Anton Glieder、Zhi Li
DOI:10.1021/cs400992z
日期:2014.2.7
85–89% for 5 diols; 65% for 1 diol). E. coli (SSP1) and E. coli (SST1) catalyzed the trans-dihydroxylation of trans-aryl olefin 16a and cis-aryl olefin 17a with excellent and complementary stereoselectivity, giving each of the four stereoisomers of 1-phenyl-1,2-propanediol 16c in high ee and de, respectively. Both strains catalyzed the trans-dihydroxylation of aryl cyclic olefins 18a and 19a to afford
Production Of Enantiopure alpha-Hydroxy Carboxylic Acids From Alkenes By Cascade Biocatalysis
申请人:NATIONAL UNIVERSITY OF SINGAPORE
公开号:US20160097063A1
公开(公告)日:2016-04-07
The invention provides compositions comprising an alkene epoxidase and a selective epoxide hydrolase, such as a recombinant microorganism comprising a first heterologous nucleic acid encoding an alkene epoxidase and a second heterologous nucleic acid encoding a selective epoxide hydrolase. Exemplary alkene epoxidases include StyAB, while exemplary selective epoxide hydrolases include epoxide hydrolases from
Sphingomonas, Solanum tuberosum
, or
Aspergillus
. The invention also provides non-toxic methods of making enantiomerically pure vicinal diols or enantiomerically pure alpha-hydroxy carboxylic acids using these compositions and microorganisms.