作者:Peter Shapland、Edwin Vedejs
DOI:10.1021/jo040125c
日期:2004.6.1
Homoallylic phosphine boranes undergo intramolecular hydroboration upon activation by triflic acid. The reaction occurs via an intermediate B-trifluorosulfonyloxyborane complex such as 15, followed by SN1-like or SN2-like displacement of the triflate leaving group, apparently leading to the formation of a four-center transition state. In the case of trisubstituted double bonds, as in the substrates
均烯丙基膦硼烷经三氟甲磺酸活化后会发生分子内氢硼化反应。该反应通过中间体B-三氟磺酰氧基硼烷络合物如15发生,随后三氟甲磺酸酯离去基团的S N 1样或S N 2样置换,显然导致形成四中心过渡态。在三取代双键的情况下,如在基材29和32中一样,烯烃的离子氢化与内部氢硼化竞争。