Zinc Tetrafluoroborate Hydrate as a Mild Catalyst for Epoxide Ring Opening with Amines: Scope and Limitations of Metal Tetrafluoroborates and Applications in the Synthesis of Antihypertensive Drugs (<i>RS</i>)/(<i>R</i>)/(<i>S</i>)-Metoprolols
作者:Brahmam Pujala、Shivani Rana、Asit K. Chakraborti
DOI:10.1021/jo201473f
日期:2011.11.4
reaction at the benzylic carbon of the epoxide ring. A reversal of regioselectivity (91:1–69:31) in favor of the reaction at the terminal carbon of the epoxide ring was observed for reaction with morpholine. The regioselectivity was dependent on the electronic and steric factors of the epoxide and the pKa of the amine and independent of amine nucleophilicity. The role of the metal tetrafluoroborates is
已经研究了金属四氟硼酸盐与胺进行环氧化物开环反应的范围和局限性,并且发现Zn(BF 4)2 · x H 2 O是一种温和而有效的催化剂,在无溶剂条件下于200 ℃提供高收率。 rt具有出色的化学,区域和立体选择性。催化效率依次为Zn(BF 4)2 · x H 2 O≫ Cu(BF 4)2 · x H 2 O> Co(BF 4)2 ·6H 2 O≫ Fe(BF 4)2 ·6H2 O> LiBF 4与环己烯氧化物和Zn(BF 4)2 · x H 2 O≫ Co(BF 4)2 ·6H 2 O≫ Fe(BF 4)2 ·6H 2 O> Cu(BF 4)反应2 · x H 2 O,用于氧化二苯乙烯,但AgBF 4是无效的。对于苯乙烯氧化物与苯胺的反应,四氟硼酸金属具有相当的区域选择性(1:99–7:93),并且在环的苄基碳上具有优先反应。与吗啉反应时,观察到区域选择性的逆转(91:1–69:31),有
An efficient method for the ring opening of epoxides with aromatic amines catalysed by indium trichloride
Indium trichloride catalyses for the first time the formation of β-amino alcohols from epoxides and aromatic amines in dichloromethane at room temperature.
三氯化铟在室温下首次催化由环氧化物和芳族胺在二氯甲烷中形成β-氨基醇。
B<sub>2</sub>O<sub>3</sub>/Al<sub>2</sub>O<sub>3</sub> as an Efficient and Recyclable Catalyst for the Synthesis of β-Amino Alcohols under Solvent-Free Conditions
Abstract A convenient and efficient procedure for the solvent-freesynthesis of β-amino alcohols has been achieved via B2O3/Al2O3-promoted highly regioselective ring opening of epoxides with aromatic amines in good to excellent yields at room temperature. Additionally, the catalyst can be recycled without affecting the catalytic property.
guest molecule. β-Cyclodextrin catalyzes chemical reactions by supramolecular catalysis with high efficiency. No investi-gations of ringopening of epoxides with aromatic amines in the presence of β-cyclodextrin in water have been reported. Our earlier study on ester hydrolysis successfully catalyzed by β-cyclodextrin derivatives [21-23] promoted us Highly Effective Opening of Epoxides with Aromatic Amines
The homochiral metal-organic framework TAMOF-1 was used as a heterogeneous catalyst in the kineticresolution of styrene oxide by ring opening reactions with anilines. The linear products underwent a second KR resulting in an amplification of the final stereoselectivity (subtractive Horeau amplification effect). Computational studies rationalized the two successive KR while providing a deep understanding