Activation of Alkynes with B(C6F5)3 - Boron Allylation Reagents Derived from Propargyl Esters
Activation of Alkynes with B(C6F5)3 - Boron Allylation Reagents Derived from Propargyl Esters
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DOI：
10.1021/ja4110842
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发表时间：
2014-01-15
影响因子：
15
通讯作者：
Stephan, Douglas W.
中科院分区：
文献类型：
--
作者：
Hansmann, Max M.;Melen, Rebecca L.;Stephan, Douglas W.
通过Lewis酸性B(C6F5)(3)与炔丙基酯的重排反应，可以很容易地合成新型的烯丙基硼化合物。这些反应通过最初的环化、随后的开环和同时进行的C6F5基团迁移来进行。在酯氧原子附近没有二取代的情况下，烯丙基硼的迁移重排导致正式的1，3-碳硼化产物。这些烯丙基硼化合物作为烯丙化试剂与引入C-3-烯丙基片段和C6F5-单元的醛作为单一的反对映异构体。在这些反应中，(C6F5)(3)激活了炔烃，促进了重排过程，并使C6F5和R基团得以安装。
Novel allyl boron compounds are readily synthesized, via rearrangement reactions between Lewis acidic B(C6F5)(3) and propargyl esters. These reactions proceed through an initial cyclization followed by ring-opening and concurrent C6F5-group migration. In the absence of disubstitution adjacent to the ester oxygen atom, an allyl boron migration rearrangement leads to formal 1,3-carboboration products. These allyl boron compounds act as allylation reagents with aldehydes introducing both a C-3-allyl fragment and a C6F5-unit as a single anti-diastereomer. In these reactions, (C6F5)(3) activates the alkynes, prompting the rearrangement processes and enabling installations of C6F5 and R-groups.