Dialkyl acylphosphonates: a new acylating agent of alcohols
作者:Mitsuo Sekine、Akiko Kume、Tsujiaki Hata
DOI:10.1016/s0040-4039(01)81975-4
日期:1981.1
Diethyl benzoylphosphonate (1) underwent facile benzoylation of alcohols in the presence of DBU. Reactions of diols containing primary and secondary hydroxyl groups with 1 gave predominantly monobenzoates in which primary hydroxyl groups were highly selectively benzoylated. Related acylations were also described.
acyclic diols, in particular 1,2-diols, were selectively monobenzoylated in good yields by the reaction with benzoyl chloride in the presence of a catalytic amount of dimethyltin dichloride and inorganic bases such as potassium carbonate. Furthermore, the method was successfully applied to a kinetic resolution of racemic 1-phenyl-1,2-ethanediol using a chiral organotin catalyst. The ee was dependent
Size‐Induced Inversion of Selectivity in the Acylation of 1,2‐Diols
作者:Stefanie Mayr、Hendrik Zipse
DOI:10.1002/chem.202101905
日期:2021.12.23
Lewis-base catalyzed acylation of aromatic 1,2-ethylenediols with anhydrides depends strongly on the size of the reagents and the π-system of the diol. Steric effects have a larger impact on reactions of primary hydroxyl groups in the 1,2-diol as well as the monoester than those of secondary hydroxyl groups. For sterically demanding anhydrides this flips the selectivity towards secondaryalcohols.
Efficient Ring Opening Reaction of Epoxides with Oxygen Nucleophiles Catalyzed by Quaternary Onium Salt
作者:Jin Won Kim、Dae Won Cho、Gyoosoon Park、Sung Hong Kim、Choon Sup Ra
DOI:10.5012/bkcs.2013.34.8.2286
日期:2013.8.20
Ring opening reactions of epoxides with oxygen nucleophiles catalyzed by a variety of quaternary onium salt, such as ammonium or phosphonium salt were explored. The results showed that tetrabutylphosphonium bromide (TBPB) among salts serves as the most efficient catalyst for this process and that expoxide ring opening reactions with a variety of oxygen nucleophiles including carboxyic acid and phenol
The Activation of Carboxylic Acids via Self-Assembly Asymmetric Organocatalysis: A Combined Experimental and Computational Investigation
作者:Mattia Riccardo Monaco、Daniele Fazzi、Nobuya Tsuji、Markus Leutzsch、Saihu Liao、Walter Thiel、Benjamin List
DOI:10.1021/jacs.6b09179
日期:2016.11.9
The heterodimerizing self-assembly between a phosphoric acid catalyst and a carboxylic acid has recently been established as a new activation mode in Brønsted acid catalysis. In this article, we present a comprehensive mechanistic investigation on this activation principle, which eventually led to its elucidation. Detailed studies are reported, including computational investigations on the supramolecular
磷酸催化剂和羧酸之间的异二聚化自组装最近已被确立为布朗斯台德酸催化中的一种新活化模式。在本文中,我们对该激活原理进行了全面的机理研究,最终对其进行了阐明。报告了详细的研究,包括对超分子异二聚体的计算研究、催化循环的动力学研究,以及通过 DFT 计算对过渡态进行彻底分析,以合理化催化剂结构 - 选择性关系。在这些研究的基础上,我们开发了外消旋环氧化物的动力学拆分,其具有高选择性(高达 s = 93),以高对映纯度提供未反应的环氧化物和相应的受保护的 1,2-二醇。而且,