Benzotriazole-Assisted Thioacylation

Abstract

[Chemical reaction: See text] Benzotriazole reagents for thioacylation (RCSBt), thiocarbamoylation (RR'NCSBt), aryl/alkoxythioacylation (ROCSBt), and aryl/alkylthiothioacylation (RSCSBt) are synthesized, and their utility is assessed by syntheses of representative heteroaryl thioureas 3a-g, thioamides 15a-s, thionoesters 16a-h, thiocarbamates 17a-e, dithiocarbamates 18a-d, thiocarbonates 19a-c, and dithiocarbonates 20a-c.

Five‐Membered Heterocycles with Three Heteroatoms: Triazoles

“…NAlkane-, N-arene-, and N-heteroenesulfonylbenzenetriazoles 129 have been exploited as efficient sulfonylating agents [185]. Several benzotriazole sulfur reagents 130 have been prepared and used for thioacylations, thiocarbamoylations, alkyl/ alkoxythioacylations, and aryl/alkylthioacylations [186]. Benzotriazole of 3,3,3-trifluoro-2-methoxy-2-phenylpropionic acid (131) reacted with water-soluble amino acids and peptides in an acetonitrile/water (2 : 1) mixture to give the corresponding Mosher derivative in quantitative yield [187].…”

Bis(benzotriazolyl)methanethione

“…1,2 Compared to thiophosgene, bis-(benzotriazolyl)methanethione is found to be more advantageous due to its high stability and less toxicity. It is a crystalline solid, easy to handle, and it can be stored for years at room temperature.…”

Trapping Reactive Intermediates by Mechanochemistry: Elusive Aryl N‐Thiocarbamoylbenzotriazoles as Bench‐Stable Reagents

“…Scheme 1. a,b) In contrast to solution chemistry, [14][15][16] mechanochemical reactions of 1 and anilines give N-thiocarbamoylbenzotriazoles (2 a-g) as stable solids which, upon milling with anilines and a base, afford thioureas (3 a-g). [b] 4-NH 2 -9 9 3 a 4-Br 4-Br 97 [c] [c,d] 3 g 4-Br 2-NH 2 98 [d,e] [a] 10 min LAG with CH 3 CN (h = 0.25 mL mg À1 ), 10 mm ball.…”

“…[b] (Figure 1 a). While 1 is a known reagent for base-catalyzed thioacylations and thiocarbamoylations in solution, [7,14] thereby giving benzotriazole (HBt) as a byproduct, its mechanochemical reactivity is still unexplored. Monitoring the reaction in situ reveals that characteristic bands of 1 are completely replaced with those of 3 a (e.g.…”

“…Katritzky et al proposed that 1 reacts with anilines in solution via reactive aryl N-thiocarbamoylbenzotriazole intermediates that are not isolable due to their rapid fragmentation into isothiocyanates (Scheme 1). [14][15][16] Speculating that the herein observed intermediate might be the elusive N-thiocarbamoylbenzotriazole, we repeated the milling without a base, and with only one equivalent of aniline. Under these conditions the intermediate was obtained as the only product (see the Supporting Information).…”