Asymmetric alkyldifluoroboranes and their use in secondary amine synthesis
Asymmetric alkyldifluoroboranes and their use in secondary amine synthesis
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DOI：
10.1021/ol025973d
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发表时间：
2002-06-27
期刊：
影响因子：
5.2
通讯作者：
Kim, GY
中科院分区：
文献类型：
--
作者：
Matteson, DS;Kim, GY
[图表]不对称二醇硼酸酯与氟化氢钾在温和条件下形成相应的烷基三氟硼酸酯和游离二醇。用四氯硅烷脱氟产生烷基二氟硼烷中间体。这种相对惰性的硼酸酯向强路易斯酸衍生物的转化开辟了新的合成机会，如通过(2-苯基-4-叠氮丁基)三氟硼酸钾从蒎二醇或1,2-二环己基-1,2-乙二醇硼酸酯在98% ee中制备(R)-2-苯基吡咯烷所说明的那样。
[GRAPHICS]Asymmetric diol boronic esters with potassium bifluoride form the corresponding alkyltrifluoroborate and free diol under mild conditions. Defluoridation with tetrachlorosilane produces an alkyldifluoroborane intermediate. This conversion of relatively unreactive boronic esters to derivatives that are strong Lewis acids opens new synthetic opportunities, as illustrated by the preparation of (R)-2-phenylpyrrolidine in 98% ee from a pinanediol or 1,2-dicyclohexyl-1,2-ethanediol boronic ester via potassium (2-phenyl-4-azidobutyl)trifluoroborate.