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Mild Ring-Opening 1,3-Hydroborations of Non-Activated Cyclopropanes
Di Wang1, Xiao-Song Xue2,3, Kendall N Houk2
1State Key Laboratory of Coordination Chemistry, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing, 210093, China.
Abstract:
The Brown hydroboration reaction, first reported in 1957, is the addition of B-H across an olefin in an anti-Markovnikov fashion. Here, we solved a long-standing problem on mild 1,3-hydroborations of non-activated cyclopropanes. A three-component system including cyclopropanes, boron halides, and hydrosilanes has been developed for borylative ring-opening of cyclopropanes following the anti-Markovnikov rule, under mild reaction conditions. Density functional theory (M06-2X) calculations show that the preferred pathway involves a cationic boron intermediate which is quenched by hydride transfer from the silane.
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