Stratingh Institute for Chemistry, University of Groningen, Groningen 9747 AG, The Netherlands.
Org Lett. 2022 Jul 29;24(29):5339-5344. doi: 10.1021/acs.orglett.2c01992. Epub 2022 Jul 17.
To circumvent protecting groups, the site-selective modification of unprotected glycosides is intensively studied. We show that site-selective oxidation, followed by treatment of the corresponding trityl hydrazone with butyl hypochlorite and a H atom donor provides an effective way to introduce a chloride substituent in a variety of mono- and disaccharides. The stereoselectivity can be steered, and a new geminal dichlorination reaction is described as well. This strategy challenges existing methods that lead to overchlorination.
为了规避保护基团，人们正在深入研究非保护型糖苷的选择性修饰方法。我们表明，选择性氧化，随后用丁基次氯酸盐和氢原子供体处理相应的三苯甲基腙，为在各种单糖和二糖中引入氯取代基提供了一种有效的方法。立体选择性可以得到控制，并且还描述了一种新的偕二氯代反应。这种策略对现有的导致过度氯化的方法提出了挑战。
