Department of Chemistry & Chemical Biology , Harvard University , Cambridge , Massachusetts 02138 , United States.
J Am Chem Soc. 2020 Feb 26;142(8):4061-4069. doi: 10.1021/jacs.0c00335. Epub 2020 Feb 14.
We report a new method for stereoselective -furanosylation reactions promoted by a precisely tailored bis-thiourea hydrogen-bond-donor catalyst. Furanosyl donors outfitted with an anomeric dialkylphosphate leaving group undergo substitution with high anomeric selectivity, providing access to the challenging 1,2- substitution pattern with a range of alcohol acceptors. A variety of stereochemically distinct, benzyl-protected glycosyl donors were engaged successfully as substrates. Mechanistic studies support a stereospecific mechanism in which rate-determining substitution occurs from a catalyst-donor resting-state complex.
我们报告了一种新的方法，用于由精确定制的双硫脲氢键供体催化剂促进的立体选择性呋喃糖基化反应。用糖基供体配备的一个糖基离去基团，经历取代反应具有高的端基选择性，为各种醇受体提供了具有挑战性的 1,2-取代模式。各种立体化学不同的、苄基保护的糖基供体作为底物成功地参与了反应。机理研究支持一种立体特异性机制，其中速率决定取代反应发生在催化剂-供体的静止状态复合物中。
