《Stereoselective Bromoboration of Acetylene with Boron Tribromide: Preparation and Cross-Coupling Reactions of (Z)-Bromovinylboronates》 was published in Journal of Organic Chemistry in 2020. These research results belong to Polasek, Jan; Paciorek, Jan; Stosek, Jakub; Semrad, Hugo; Munzarova, Marketa; Mazal, Ctibor. Quality Control of 1-Bromo-3,4,5-trimethoxybenzene The article mentions the following:
The mechanism of acetylene bromoboration in neat boron tribromide was studied carefully by means of experiment and theory. Besides the syn-addition mechanism through a four-center transition state, radical and polar anti-addition mechanisms are postulated, both triggered by HBr, which is evidenced also to take part in the Z/E isomerization of the product. The proposed mechanism is well supported by ab initio calculations at the MP2/6-31+G* level with Ahlrichs’ SVP all-electron basis for Br. Implicit solvation in CH2Cl2 has been included using the PCM and/or SMD continuum solvent models. Comparative case studies have been performed involving the B3LYP/6-31+G* with Ahlrichs’ SVP for Br and MP2/Def2TZVPP levels. The mechanistic studies resulted in development of a procedure for stereoselective bromoboration of acetylene yielding E/Z mixtures of dibromo(bromovinyl)borane (I) with the Z-isomer as a major product (up to 85%). Transformation to the corresponding pinacol and neopentyl glycol boronates and stereoselective decomposition of their E-isomer provided pure (Z)-(2-bromovinyl)boronates in 57-60% overall yield. Their reactivity in a Negishi cross-coupling reaction was tested. An example of the one-pot reaction sequence of Negishi and Suzuki-Miyaura cross-couplings for synthesis of combretastatin A4 is also presented. After reading the article, we found that the author used 1-Bromo-3,4,5-trimethoxybenzene(cas: 2675-79-8Quality Control of 1-Bromo-3,4,5-trimethoxybenzene)
1-Bromo-3,4,5-trimethoxybenzene(cas: 2675-79-8) is an important raw material and intermediate used in organic synthesis, pharmaceuticals, agrochemicals and dyestuff.Quality Control of 1-Bromo-3,4,5-trimethoxybenzene1-Bromo-3,4,5-trimethoxybenzene can be used to synthesize N,N′-diarylated indolo[3,2-b]carbazole derivatives, which can find applications in electrophotography.
Referemce:
Bromide – Wikipedia,
bromide – Wiktionary