Examining Trichloroisocyanuric Acid and Oxalyl Chloride in Complementary Approaches to Fluorination of Group 15 Heteroatoms

Abstract

A mild, oxidative fluorination approach to a variety of fluorinated phosphorus compounds using trichloroisocyanuric acid (TCICA) and KF was developed as a complement to a recent study on deoxygenative fluorination using oxalyl chloride. Herein, the syntheses of several fluorinated organophosphorus compounds are reported, and both TCICA/KF and oxalyl chloride/KF conditions are compared and contrasted throughout. Initial investigations of the method on other group 15 heteroatoms (i. e., As, Sb, and Bi) are also reported, with varied success. This work notably extends the known TCICA/KF reactivity series to another group of elements beyond previously studied chalcogens (S, Se, and Te) and halogens (iodine) and expands the utility of the previously reported oxalyl chloride/KF method.

Solvent-free photochemical decomposition of sulfur hexafluoride by phosphines: formation of difluorophosphoranes as versatile fluorination reagents

“…39 They are usually synthesized by oxidation of the phosphines using harsh reagents such as XeF 2 , SF 4 , HgF 2 or N 2 F 4 , 40 but more convenient protocols have been recently developed. 41…”

Oxidative Fluorination of Heteroatoms Enabled by Trichloroisocyanuric Acid and Potassium Fluoride

“…We also briefly explored applications of TCICA/KF with Group 15 heteroatoms (e.g., in the difluorination of triarylphosphines and triarylarsines). [59] These results are not discussed herein, as we concede that the TCICA/KF approach may not be the best way to access a vast majority of fluorinated phosphorus-, arsenic-, and antimony-based compounds (a deoxygenative fluorination approach seems generally more prudent [60] ). But, in any case, while traversing Groups 15-17 of the periodic table, we never really lost interest in SF 5 chemistry-where our journey began.…”

“…Over a two‐year stint, curiosity had led us to explore oxidative fluorination of sulfur, selenium, and tellurium, as well as iodine, on various organic frameworks. We also briefly explored applications of TCICA/KF with Group 15 heteroatoms (e.g., in the difluorination of triarylphosphines and triarylarsines) [59] . These results are not discussed herein, as we concede that the TCICA/KF approach may not be the best way to access a vast majority of fluorinated phosphorus‐, arsenic‐, and antimony‐based compounds (a deoxygenative fluorination approach seems generally more prudent [60] ).…”

Recent Developments in Nucleophilic Fluorination with Potassium Fluoride (KF): A Review

“…The limitation of the TCICA/KF method is the tedious purification step and the oxalyl chloride/KF method is the high cost of oxalyl chloride. [58]…”

“…Further, the oxalyl chloride ((COCl) 2 ) reagent has not tolerated ortho ‐Me‐substitution, as compound 94 i was not formed and the TCICA reagent has not tolerated the compound substituted with furyl rings 94 j . The limitation of the TCICA/KF method is the tedious purification step and the oxalyl chloride/KF method is the high cost of oxalyl chloride [58] …”