Hirner Joshua J, Faizi Darius J, Blum Suzanne A
Department of Chemistry, University of California, Irvine , Irvine, California 92617-2025, United States.
J Am Chem Soc. 2014 Mar 26;136(12):4740-5. doi: 10.1021/ja500463p. Epub 2014 Mar 14.
For nearly 70 years, the addition of boron-X σ bonds to carbon-carbon multiple bonds has been employed in the preparation of organoboron reagents. However, the significantly higher strength of boron-oxygen bonds has thus far precluded their activation for addition, preventing a direct route to access a potentially valuable class of oxygen-containing organoboron reagents for divergent synthesis. We herein report the realization of an alkoxyboration reaction, the addition of boron-oxygen σ bonds to alkynes. Functionalized O-heterocyclic boronic acid derivatives are produced using this transformation, which is mild and exhibits broad functional group compatibility. Our results demonstrate activation of this boron-O σ bond using a gold catalysis strategy that is fundamentally different from that used previously for other boron addition reactions.
近70年来，硼-碳σ键加成到碳-碳多重键上一直被用于制备有机硼试剂。然而，硼-氧键的强度明显更高，迄今为止阻碍了它们的加成活化，从而阻止了直接获得一类潜在有价值的用于发散合成的含氧有机硼试剂的途径。我们在此报告了一种烷氧基硼化反应的实现，即硼-氧σ键加成到炔烃上。通过这种温和且具有广泛官能团兼容性的转化反应，可以制备官能化的O-杂环硼酸衍生物。我们的结果表明，使用一种与先前用于其他硼加成反应的策略根本不同的金催化策略，可以实现这种硼-氧σ键的活化。
