A practical chlorination of tert-butyl esters with PCl₃ generating acid chlorides

Abstract

For the first time, using PCl3, a range of tert-butyl esters is chlorinated successfully, allowing access of both aromatic acid chlorides and aliphatic acid chlorides in good yields. The method features simple reaction conditions and wide substrate scope. Various tert-butyl esters including aryl esters, alkenyl esters, and alkyl esters were tolerated well in the reaction. A plausible mechanism is proposed.

Iodine Promoted Conversion of Esters to Nitriles and Ketones under Metal-Free Conditions

“…Although the detailed mechanism was unclear, on the basis of the above results and previous reports, , plausible reaction pathways were proposed in Scheme . First, PCl 3 reacted with H 2 O which existed in the air or solvent to give HCl.…”

“…Molecular iodine is a simple and readily available chemical which was used in various oxidation reactions, deprotecting reactions, and other transformations . Recently, we are interested in the applications of phosphorus compounds and iodine in organic synthesis . As a part of our ongoing research, we envisioned that, if nitriles and ketones could be prepared from esters in the presence of I 2 and PCl 3 , a cheap, simple, and metal-free reaction for the synthesis of these products will be developed.…”

Tin(II) Chloride-Catalyzed Direct Esterification and Amidation of tert-Butyl Esters Using α,α-Dichlorodiphenylmethane Under Mild Conditions

“…However, only a few methods for direct transformation of tert -butyl esters to acid chlorides have been reported. For example, acid chlorides were directly prepared from tert -butyl esters using phosphorus trichloride (PCl 3 ) . However, PCl 3 is a reactive and toxic chemical, and PCl 3 -mediated reactions were conducted under harsh reaction conditions, including high temperature.…”

“…For example, acid chlorides were directly prepared from tert-butyl esters using phosphorus trichloride (PCl 3 ). 18 However, PCl 3 is a reactive and toxic chemical, and PCl 3 -mediated reactions were conducted under harsh reaction conditions, including high temperature. Thus, the development of a new, efficient, direct transformation of tert-butyl ester to acid chloride under mild reaction conditions is a valuable area of study for the production of target esters or amides.…”