Controlled Exchange of Achiral Linkers with Chiral Linkers in Zr-Based UiO-68 Metal–Organic Framework
作者:Chunxia Tan、Xing Han、Zijian Li、Yan Liu、Yong Cui
DOI:10.1021/jacs.8b09606
日期:2018.11.28
linker MOFs are active and efficient catalysts for asymmetric cyanosilylation of aldehydes, ring-opening of epoxides, oxidative kinetic resolution of secondary alcohols, and aminolysis of stilbene oxide, and the mixed-M(salen) linker variants are active for sequential asymmetric alkeneepoxidation/epoxide ring-opening reactions. The chiral MOF catalysts are highly enantioselective and completely heterogeneous
Design and Assembly of a Chiral Metallosalen-Based Octahedral Coordination Cage for Supramolecular Asymmetric Catalysis
作者:Chunxia Tan、Jingjing Jiao、Zijian Li、Yan Liu、Xing Han、Yong Cui
DOI:10.1002/anie.201711310
日期:2018.2.19
and high enantioselectivity represent a design challenge of practical importance. Herein, it is demonstrated that a chiral octahedral coordinationcage can be constructed by using twelve enantiopure Mn(salen)‐derived dicarboxylic acids as linear linkers and six Zn4‐p‐tert‐butylsulfonylcalix[4]arene clusters as tetravalent four‐connected vertices. The porous cage features a large hydrophobic cavity (≈3944 Å3)
Asymmetric Counteranion-Directed Transition-Metal Catalysis: Enantioselective Epoxidation of Alkenes with Manganese(III) Salen Phosphate Complexes
作者:Saihu Liao、Benjamin List
DOI:10.1002/anie.200905332
日期:2010.1.12
Paired up: A highly active and enantioselective ion‐pair epoxidationcatalyst, consisting of an achiral MnIII–salen complex and a chiral phosphate counteranion, mediates the epoxidization of a wide range of alkenes with high yields and enantioselectivities (see scheme). The unique role of the counteranion is to stabilize an enantiomorphic conformation of the cationic Mn catalyst.
配对:高活性和对映选择性离子对环氧化催化剂,由非手性Mn III -salen配合物和手性磷酸抗衡阴离子组成,可介导高产率和对映选择性的多种烯烃的环氧化。抗衡阴离子的独特作用是稳定阳离子Mn催化剂的对映体构象。
An efficient and simple method for synthesis of 2,2-disubstituted-2H-chromenes by condensation of a phenol with a 1,1-disubstituted propargyl alcohol using BF3·Et2O as the catalyst
An efficient and simple method for the synthesis of 2,2-disubstituted-2H-chromenes by one-step cyclocondensation of a phenol with a variety of 1,1-disubstituted propargyl alcohols using BF3·Et2O as the catalyst is described.
ReCl(CO)5-catalyzed cyclocondensation of phenols with 2-methyl-3-butyn-2-ol to afford 2,2-dimethyl-2H-chromenes
作者:Hanxiang Zeng、Jia Ju、Ruimao Hua
DOI:10.1016/j.tetlet.2011.05.093
日期:2011.7
A direct one-pot route for the synthesis of 2,2-dimethyl-2H-chromenes by Re(CO)5Cl-catalyzed cyclocondensation of phenols with 2-methyl-3-butyn-2-ol has been developed. The easy availability of starting materials, mild reaction conditions, high atom-efficiency, and the use of a recoverable catalyst are advantages of this procedure.