开发了一种使用硅胶和 H 2 O水解有机三氟硼酸盐以揭示硼酸的通用、温和且有效的方法。事实证明,该方法可以耐受各种芳基-、杂芳基-、烯基-和烷基三氟硼酸盐以及结构多样的氨甲基化有机三氟硼酸盐。正如预期的那样,由于共振稳定的二氟硼烷中间体,富电子底物比缺电子底物更容易提供相应的硼酸。开发的方法进一步扩展用于将有机三氟硼酸盐转化为相应的硼酸酯。
Expanding the Balz-Schiemann Reaction: Organotrifluoroborates Serve as Competent Sources of Fluoride Ion for Fluoro-Dediazoniation
作者:Tharwat Mohy El Dine、Omar Sadek、Emmanuel Gras、David M. Perrin
DOI:10.1002/chem.201803575
日期:2018.10.9
The Balz–Schiemann reaction endures as a method for the preparation of (hetero)aryl fluorides yet is eschewed due to the need for harsh conditions or high temperatures along with the need to isolate potentially explosive diazonium salts. In a departure from these conditions, we show that various organotrifluoroborates (RBF3−s) may serve as fluorideion sources for solution‐phase fluoro‐dediazoniation
Unlike their ortho counterparts, meta- and para-acetamidoanilines can be converted into the corresponding acetamidoarenediazoniumsalts. These offer various opportunities for multiple Pd-catalyzed arene functionalization reactions, such as Matsuda-Heck-, Suzuki-Miyaura- or Fujiwara-Moritani couplings.
Additive- and Photocatalyst-Free Borylation of Arylazo Sulfones under Visible Light
作者:Yuliang Xu、Xinying Yang、Hao Fang
DOI:10.1021/acs.joc.8b01662
日期:2018.10.19
developed a photocatalyst-free and additive-free, visible light induced borylation reaction using arylazo sulfones as starting material. This protocol shows some advantages such as mild conditions, simple equipment, and wide substrate scope, which gives a complementary protocol for the preparation of arylboronates.
Efficient metal-free photochemical borylation of aryl halides under batch and continuous-flow conditions
作者:Kai Chen、Shuai Zhang、Pei He、Pengfei Li
DOI:10.1039/c5sc04521e
日期:——
A rapid, chemoselective and metal-free C-B bond-forming reaction of aryl iodides and bromides in aqueous solution at low temperatures was discovered. This reaction is amenable to batch and continuous-flow conditions...
Transition-Metal-Free Borylation of Aryl Bromide Using a Simple Diboron Source
作者:Taeho Lim、Jeong Yup Ryoo、Min Su Han
DOI:10.1021/acs.joc.0c01065
日期:2020.8.21
reaction of aryl bromides. Bis-boronic acid (BBA), was used, and the borylation reaction was performed using a simple procedure at a mild temperature. Under mild conditions, aryl bromides were converted to arylboronic acids directly without any deprotection steps and purified by conversion to trifluoroborate salts. The functional group tolerance was considerably high. The mechanism study suggested that