61936-85-4Relevant academic research and scientific papers
Metal-Free Directed C?H Borylation of Pyrroles
Wang, Zheng-Jun,Chen, Xiangyang,Wu, Lei,Wong, Jonathan J.,Liang, Yong,Zhao, Yue,Houk, Kendall N.,Shi, Zhuangzhi
, p. 8500 - 8504 (2021)
Robust strategies to enable the rapid construction of complex organoboronates in selective, practical, low-cost, and environmentally friendly modes remain conspicuously underdeveloped. Here, we develop a general strategy for the site-selective C?H borylation of pyrroles by using only BBr3 directed by pivaloyl groups, avoiding the use of any metal. The site-selectivity is generally dominated by chelation and electronic effects, thus forming diverse C2-borylated pyrroles against the steric effect. The formed products can readily engage in downstream transformations, enabling a step-economic process to access drugs such as Lipitor. DFT calculations (wB97X-D) demonstrate the preferred positional selectivity of this reaction.
