143900-49-6Relevant articles and documents
Catalytic Activation of Cis-Vicinal Diols by Boronic Acids: Site-Selective Acylation of Carbohydrates
Shimada, Naoyuki,Nakamura, Yuki,Ochiai, Takayuki,Makino, Kazuishi
supporting information, p. 3789 - 3794 (2019/05/24)
Site-selective acylation of unprotected carbohydrates by using stable, storable, and easily handled imidazole-containing organoboronic acid catalysts is described. This catalytic process with low catalyst loading enables the introduction of a wide variety of acyl functional groups into the equatorial position of cis-vicinal diols in unprotected hexapyranosides with excellent site selectivity. This is the first example that uses a Lewis base-containing boronic acid to enhance the nucleophilicity of hydroxy groups.
Site-Selective Acylations with Tailor-Made Catalysts
Huber, Florian,Kirsch, Stefan F.
supporting information, p. 5914 - 5918 (2016/04/26)
The acylation of alcohols catalyzed by N,N-dimethylamino pyridine (DMAP) is, despite its widespread use, sometimes confronted with substrate-specific problems: For example, target compounds with multiple hydroxy groups may show insufficient selectivity for one hydroxyl, and the resulting product mixtures are hardly separable. Here we describe a concept that aims at tailor-made catalysts for the site-specific acylation. To this end, we introduce a catalyst library where each entry is constructed by connecting a variable and readily tuned peptide scaffold with a catalytically active unit based on DMAP. For selected examples, we demonstrate how library screening leads to the identification of optimized catalysts, and the substrates of interest can be converted with a markedly enhanced site-selectivity compared with only DMAP. Furthermore, substrate-optimized catalysts of this type can be used to selectively convert "their" substrate in the presence of structurally similar compounds, an important requisite for reactions with mixtures of substances. Substrate-optimized catalysts: Site- selective acylations were achieved using substrate-optimized catalysts (see scheme) as identified from a library screening. The catalysts are composed of low-molecular-weight peptides that are readily tuned through variation of the amino acid sequence, and one amino acid was connected to DMAP to ensure catalytic activity. These substrate-optimized catalysts were also applied to selectively convert one substrate in the presence of a structurally similar compound.
Regioselective benzoylation of glycopyranosides by benzoyl chloride in the presence of MoO2(acac)2
Evtushenko
experimental part, p. 369 - 378 (2012/06/04)
Benzoylation of methyl and benzyl glycopyranosides by benzoyl chloride in the presence of MoO2(acac)2 as a catalyst resulted in 3-benzoates with good yield and high regioselectivity. Simple synthesis of the monobenzoates of some glyc
