TIN-COPPER TRANSMETALATION - CROSS-COUPLING OF ALPHA-HETEROATOM-SUBSTITUTED ALKYLTRIBUTYLSTANNANES WITH ORGANOHALIDES
TIN-COPPER TRANSMETALATION - CROSS-COUPLING OF ALPHA-HETEROATOM-SUBSTITUTED ALKYLTRIBUTYLSTANNANES WITH ORGANOHALIDES
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DOI：
10.1021/ja00127a010
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发表时间：
1995-06-07
影响因子：
15
通讯作者：
YE, JH
中科院分区：
文献类型：
--
作者：
FALCK, JR;BHATT, RK;YE, JH
在不存在其它过渡金属的情况下，铜（I）催化（α-（酰氧基）苄基）-三丁基锡烷与烯丙基溴在THF中的交叉偶联，产率相当好，而与芳基/乙烯基卤化物的交叉偶联效率较低或根本不催化。简单的（α-（酰氧）烷基）三丁基锡烷即使与烯丙基溴反应也很缓慢。然而，在任一反应伴侣上的近端硫代取代基显著提高产率、反应速率和合适的离析物的种类。（α-邻苯二甲酰亚胺基烷基）三丁基锡烷提供保护的α-氨基硫代酯。与Stille反应相反，铜介导的α-杂原子取代的烷基三丁基锡烷的交叉偶联通过配位稳定的有机铜中间体进行，其可以通过与2-环己烯-1-酮的1，4-共轭加成以良好的产率截取，从而完全保留构型。
Copper(I), in the absence of other transition metals, catalyzes the cross-coupling of (alpha-(acyloxy)benzyl)-tributylstannanes with allylic bromides in THF in fair to good yields and with aryl/vinyl halides less efficiently or not at all. Simple (alpha-(acyloxy)alkyl)tributylstannanes react sluggishly even with allyl bromide. However, proximal thiosubstituents on either reaction partner dramatically enhance yields, reaction rates, and the variety of suitable educts. (alpha-Phthalimidoylalkyl)tributylstannanes afford protected a-amino thio esters. In contrast with the Stille reaction, copper-mediated cross-couplings of alpha-heteroatom-substituted alkyltributylstannanes proceed with complete retention of configuration via a coordinatively stabilized organocopper intermediate that can be intercepted in good yield by 1,4-conjugate addition to 2-cyclohexen-1-one.