Benzoxaborole Catalyst for Site-Selective Modification of Polyols
Benzoxaborole Catalyst for Site-Selective Modification of Polyols
复制标题
DOI：
10.1002/ejoc.201901749
复制
发表时间：
2020-02-03
影响因子：
2.8
通讯作者：
Hayashida, Osamu
中科院分区：
文献类型：
--
作者：
Kusano, Shuhei;Miyamoto, Shoto;Hayashida, Osamu
在不使用保护基的情况下，含多个羟基的多元醇的位置选择性修饰仍然是合成化学中的一个重大挑战。为了解决这一问题，人们设计了一种新型的苯并恶硼化合物作为高效的催化剂，用于多元醇的高位置选择性和无保护基改性。为了确定提高催化活性和选择性的有效取代基团，合成了一系列苯并恶硼化合物催化剂1a-k。对取代基效应的深入分析表明，1I-k具有多个含氟和三氟甲基吸电子基团，具有最高的催化活性和选择性。此外，~1I催化的各种顺-1，2-二醇衍生物的苯甲酰化、对甲苯磺化、苯甲化和糖基化反应都以良好的产率和位置选择性进行。
The site-selective modification of polyols bearing several hydroxyl groups without the use of protecting groups remains a significant challenge in synthetic chemistry. To address this problem, novel benzoxaborole derivatives were designed as efficient catalysts for the highly site-selective and protecting-group-free modification of polyols. To identify the effective substituent groups enhancing the catalytic activity and selectivity, a series of benzoxaborole catalysts 1a-k were synthesized. In-depth analysis for the substituent effect revealed that 1i-k, bearing multiple electron-withdrawing fluoro- and trifluoromethyl groups, exhibited the greatest catalytic activity and selectivity. Moreover, 1i-catalyzed benzoylation, tosylation, benzylation, and glycosylation of various cis-1,2-diol derivatives proceeded with good yield and site-selective manner.