作者:Daniel Meyer、Philippe Renaud
DOI:10.1002/anie.201703340
日期:2017.8.28
A one-pot procedure for the enantioselective hydroazidation of non-activated trisubstituted alkenes is described. Hydroboration with monoisopinocampheylborane (IpcBH2) provides dialkylboranes that are in situ selectively converted into monoalkyl-substituted catecholboranes; these undergo radical azidation upon treatment with benzenesulfonyl azide and a radical initiator. Enantiomerically enriched azides
描述了用于非活化三取代烯烃的对映选择性加氢叠氮的一锅法方法。用单异opinocampheylborane(IpcBH 2)进行硼氢化反应可生成二烷基硼烷,该二烷基硼烷可在原位选择性转化为单烷基取代的儿茶酚硼烷;它们在用苯磺酰叠氮化物和自由基引发剂处理后进行自由基叠氮化。因此获得对映体富集的叠氮化物,产率为59-81%,对映选择性高达94:6 er(如果中间体二烷基硼烷通过结晶纯化则为98:2 er)。还描述了快速获得对映体纯的(+)-罗多卡因。使用其他芳烃磺酰基自由基捕集剂可以进行对映体选择性的氢烷基化,氢磺酰化和氢溴化反应,产率为71–86%。