氢原子转移介导的C(sp^(3))-H键选择性硼基化

Hydrogen atom transfer-induced selective borylation of C(sp^(3))-H bonds

作为一种高度原子经济性和步骤经济性的策略,C(sp^(3))-H键的选择性官能团化一直备受关注.其中硼基化反应以低毒害、高效多样的转化能力,倾注了合成化学家最多的努力.然而,由于C(sp^(3))-H键的惰性,控制C(sp^(3))-H键硼基化的化学选择性和区域选择性是一项重大的挑战.作为一种新兴的方法,利用氢原子转移(HAT)实现C(sp^(3))-H键选择性硼基化相比以往过渡金属催化的过程有着其独特之处.此专题中,我们对最近兴起的各种HAT介导的C(sp^(3))-H键选择性硼基化的方法进行了分析.从分子内和分子间的HAT的角度分类,重点介绍了各种方法不同选择性的来源,并对所涉及的机理进行了具体的讨论.最后,我们整理了目前方法的局限性,并对这一领域的前景进行了展望.

As a highly atom-and step-economic strategy,the selective functionalization of C(sp^(3))-H bonds has been attracting considerable attention.Among them,borylation reactions,with their low toxicity and highly diverse transformative capabilities,have received lots of efforts from synthetic chemists.However,due to the inertness of C(sp^(3))-H bonds,controlling the chemo-and regioselectivity of C(sp^(3))-H borylation presents a significant challenge.As an emerging approach,achieving selective borylation of C(sp^(3))-H bonds through hydrogen atom transfer(HAT)offers unique advantages compared to conventional transition metal-catalyzed processes.In this review,we analyze various recent HAT-mediated methods for selective borylation of C(sp^(3))-H bonds.Categorizing them from the perspectives of intramolecular and intermolecular HAT,we emphasize the different sources of selectivity for each method and provide a detailed discussion of the involved mechanisms.Finally,we summarize the current limitations of the methods and provide outlooks for the future development in this field.