Pd‐Catalyzed Site‐Selective Borylation of Simple Arenes via Thianthrenation^†

Abstract

of main observation and conclusion Site-selective borylation of simple arenes was realized in one pot via an electrophilic thianthrenation/Pd-catalyzed borylation sequence. The key to achieve this operatically simple process is the use of Pd catalysis, which could tolerate the solvent and acidic conditions used in the thianthrenation step. This protocol features mild conditions, broad functional group tolerance, and simple manipulations, and is suitable for late-stage functionalization of a wide range of pharmaceuticals and complex bioactive molecules.

Organothianthrenium salts: synthesis and utilization

“…In 2020, Wang and co-workers discovered the para-selective borylation of monosubstituted benzenes via the formation of aryl thianthrenium salts (Scheme 16). 60,82 Borylation products ( 16) can be obtained by photocatalysis or metal catalysis. Various electron-rich mono-substituted arenes could be siteselectively borylated to deliver functionalized aryl borylation.…”

“…TsScheme 16. para-Selective borylation of monosubstituted benzenes with aryl thianthrenium salts thianthrenium salts (Scheme 16) 60,82. Borylation products (16) can be obtained by photocatalysis or metal catalysis.…”

Recent Advances in Thianthrenation/Phenoxathiination Enabled Site-Selective Functionalization of Arenes

“…Taking advantage of transition metal catalysis, the Wang group further reported a simplified procedure for the site-selective borylation of simple arenes. 33 With the new protocol, the extra manipulations for removal of the solvent and acids in the thianthrenation step are discarded, thus significantly increasing the practicality of the thianthrenation enabled site-selective borylation of arenes. Moreover, the transition metal catalysis showed better efficiency and reproducibility in comparison to that of photoredox catalysis.…”

Visible-Light-Mediated Ruthenium-Catalyzed para-Selective Alkylation of Unprotected Anilines

“…In this context, several strategies were developed to achieve para -selectivity. , Besides electrophilic C–H functionalization (S E Ar) , and special nucleophilic processes (S N Ar), the groups of Yu, Maiti, and Li designed different nitrile-accommodating biphenyl templates for para -C–H functionalization of toluene, phenol, and benzoic acid derivatives [Scheme A­(b)] . Noncovalent template strategies based on hydrogen bonding or electrostatic interaction were also developed by the groups of Chattopadhyay, Liang, and Phipps and of Maleczka [Scheme A­(c)].…”