Santi Micol, Ould Darren M C, Wenz Jan, Soltani Yashar, Melen Rebecca L, Wirth Thomas
School of Chemistry, Cardiff University, Main Building, Park Place, Cardiff, CF10 3AT, Wales, UK.
Angew Chem Int Ed Engl. 2019 Jun 3;58(23):7861-7865. doi: 10.1002/anie.201902985. Epub 2019 Apr 10.
A novel metal-free synthesis of 3,3-disubstituted benzofuran-2-(3H)-ones through reacting α-aryl-α-diazoacetates with triarylboranes is presented. Initially, triarylboranes were successfully investigated in α-arylations of α-diazoacetates, however in the presence of a heteroatom in the ortho position, the boron enolate intermediate undergoes an intramolecular rearrangement to form a quaternary center. The intermediate cyclizes to afford valuable 3,3-disubstituted benzofuranones in good yields.
本文报道了一种通过α-芳基-α-重氮乙酸酯与三芳基硼烷反应，无金属合成3,3-二取代苯并呋喃-2-(3H)-酮的新方法。最初，三芳基硼烷已成功应用于α-重氮乙酸酯的α-芳基化反应，但在邻位存在杂原子的情况下，硼烯醇盐中间体发生分子内重排形成季碳中心。该中间体环化，以良好的产率得到有价值的3,3-二取代苯并呋喃酮。
