Mukaiyama reagent-promoted metal-free preparation of alkynyl sulfones and phosphonates under mild conditions
作者:Danyang Qi、Wanrong Dong、Zhihong Peng、Yingjun Zhang、Delie An
DOI:10.1016/j.tet.2019.06.035
日期:2019.8
An efficient and mild route for the formation sulfur or phosphor-substituted alkynes was herein demonstrated. The Mukaiyama reagent-mediated transformation started from easily-accessible substrates without carbon-carbon triple bonds, and the reaction proceeded undermildconditions (room temperature) in a one-pot manner, requiring for no transition metal-catalysts. The practical protocol featured for
SmI<sub>2</sub>-mediated intermolecular addition–elimination of piperidine and pyrrolidine <i>N</i>-α-radicals with arylacetylene sulfones
作者:Chang-Hong Liu、Jia-Ming Guo、Xin Li、Jian-Ting Sun、Bang-Guo Wei、Chang-Mei Si
DOI:10.1039/d2cc03984b
日期:——
An efficient approach to access α-arylacetylene-substituted pyrrolidine and piperidine derivatives has been developed through a samarium diiodide-mediated addition–elimination process of pyrrolidine and piperidine N-α-radicals with arylacetylene sulfones.
effective synthetic methods stands in stark contrast to the large number of encumbered sites encountered in molecules of interest. Here, we demonstrate that 1,2-bis(boronates) undergo selective alkynylation and alkenylation at the more sterically hindered C–B bond. Our preliminary mechanistic studies disclosed that this reaction can proceed through two convergent pathways involving direct coupling of sterically