91685-06-2Relevant articles and documents
Stannous chloride as a low toxicity and extremely cheap catalyst for regio-/site-selective acylation with unusually broad substrate scope
Dong, Hai,Feng, Guang-Jing,Luo, Tao,Lv, Jian,Yu, Jian-Cheng
supporting information, p. 6936 - 6942 (2020/11/09)
This work reports stannous chloride (SnCl2)-catalyzed regio-/site-selective acylation with unusually broad substrate scope. In addition to 1,2- and 1,3-diols and glycosides containing cis-vicinal diol, the substrate scope also includes glycosides without cis-vicinal diol. For such a substrate scope, usually, only methods using stoichiometric amounts of organotin reagents can lead to the same protection pattern with high selectivities and highly isolated yields (84-97% in most cases). Therefore, SnCl2, as a low toxicity and extremely cheap reagent, should be the best catalyst for regio-/site-selective acylation compared with any previously reported reagents. This journal is
An inexpensive catalyst, Fe(acac)3, for regio/site-selective acylation of diols and carbohydrates containing a 1,2-: Cis -diol
Lv, Jian,Ge, Jian-Tao,Luo, Tao,Dong, Hai
supporting information, p. 1987 - 1991 (2018/05/23)
This work describes the [Fe(acac)3] (acac = acetylacetonate)-catalyzed, regio/site-selective acylation of 1,2- and 1,3-diols and glycosides containing a cis-vicinal diol. The iron(iii) catalysts initially formed cyclic dioxolane-type intermediates with substrates between the iron(iii) species and vicinal diols, and the efficient and selective acylation of one hydroxyl group was subsequently achieved by adding acylation reagents in the presence of diisopropylethylamine (DIPEA) under mild conditions. This reaction generally produced high selectivities and highly isolated yields with the same protection pattern as that achieved with dibutyl tinoxide-mediated schemes.
Enhanced site-selectivity in acylation reactions with substrate-optimized catalysts on solid supports
Tong, My Linh,Huber, Florian,Taghuo Kaptouom, Estelle S.,Cellnik, Torsten,Kirsch, Stefan F.
supporting information, p. 3086 - 3089 (2017/03/17)
A concept for site selective acylation of poly-hydroxylated substrates is presented where polymer-supported catalysts are employed: catalytically active DMAP units were combined with a library of small molecule peptides attached to the solid phase with the goal to identify substrate-optimized catalysts through library screening. For selected examples, we demonstrate how the optimized catalysts can convert “their” substrate with a markedly enhanced site-selectivity, compared to only DMAP. Due to the solid support, product purification is significantly simplified, and the peptidic catalysts can be easily reused in multiple cycles while conserving its efficiency.