New asymmetric syntheses with boronic esters and fluoroboranes
New asymmetric syntheses with boronic esters and fluoroboranes
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DOI：
10.1351/pac200375091249
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发表时间：
2003-09-01
影响因子：
1.8
通讯作者：
Matteson, DS
中科院分区：
文献类型：
--
作者：
Matteson, DS
有效裂解不对称二醇的空间位阻硼酸酯以回收二醇和更具反应性的硼烷衍生物一直是一个具有挑战性的问题。一个显着的硼硅酸盐玻璃催化裂解与亚硫酰氯和咪唑证明不如预期的有用。氟化氢钾将硼酸酯转化为二醇和烷基三氟硼酸酯。这些与氯硅烷产生烷基二氟硼烷，其与烷基叠氮化物形成高对映体纯度的仲胺。
Efficient cleavage of sterically hindered boronic esters of asymmetric diols to recover both the diol and a more reactive borane derivative has been a challenging problem. A remarkable borosilicate glass-catalyzed cleavage with thionyl chloride and imidazole proved less useful than hoped for. Potassium bifluoride converts boronic esters to diols and alkyltrifluoroborates. These with chlorosilanes yield alkyldifluoroboranes, which with alkyl azides form secondary amines in high enantiopurity.