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
Branched Amine Synthesis via Aziridine or Azetidine Opening with Organotrifluoroborates by Cooperative Brønsted/Lewis Acid Catalysis: An Acid-Dependent Divergent Mechanism
作者:Truong N. Nguyen、Jeremy A. May
DOI:10.1021/acs.orglett.8b01394
日期:2018.6.15
A practical catalytic method to synthesize β,β- and γ,γ-substituted amines by opening aziridines and azetidines, respectively, using alkenyl, alkynyl, or aryl/heteroaryl trifluoroborate salts is described. This reaction features simple open-flask reaction conditions, the use of transition-metal-free catalysis, complete regioselectivity, and high diastereoselectivity. Preliminary mechanistic studies
A direct cross-coupling reaction of aromatic aldehydes with potassiumtrifluoro(organo)borates afforded ketones in high yields and under mild conditions in the presence of a rhodium catalyst and acetone. This new reaction, involving a formal aldehyde C-H bond activation, is believed to proceed via a Heck-type mechanism followed by hydride transfer to acetone.
Pd-Catalysed Suzuki coupling of α-bromoethenylphosphonates with organotrifluoroborates: a general protocol for the synthesis of terminal α-substituted vinylphosphonates
and robust protocol for the synthesis of terminal α-substituted vinylphosphonates via Suzuki coupling of α-bromovinylphosphonates with organotrifluoroborates has been successfully developed. This method features broad substrate scope, great functional group compatibilities, and easy scale-up ability. In addition to easy access of nucleophiles, straightforwardsynthesis of electrophiles was also realized
Aryl radical-induced desulfonylative<i>ipso</i>-substitution of diaryliodonium salts: an efficient route to sterically hindered biarylamines
作者:Huangguan Chen、Limin Wang、Jianwei Han
DOI:10.1039/d0cc01766c
日期:——
By using vicinal aryl sulfonamide substituted diaryliodonium salts, a cascade of desulfonylation/aryl migration was promoted by triethylamine in the synthesis of sterically hindered biarylamines, which operated via a radical-induced reaction pathway. The products were readily converted into a variety of important synthons. Furthermore, coupling reactions of N-methyl biarylamine and 1,6-dibromopyrene