Esters as Both Alkylating and Acylating Reagents: PCl₃‐Promoted Friedel‐Crafts Reaction in One‐Pot

Abstract

An efficient PCl 3 -promoted Friedel-Crafts reaction using esters as both alkylating and acylating reagents has been developed. By using a PCl 3 /I 2 combination, various esters underwent Friedel-Crafts alkylation and acylation reactions with arenes in one-pot, readily producing two kinds of products aromatic ketones and alkyl aromatics by one step in good yields. The Friedel-Crafts alkylation and acylation of arene with 4-formylbenzoate derivatives in one-pot have also been achieved. This novel strategy features high step economy, low-cost, metal-free and simple reaction conditions.

Iodine and Iodide in Reductive Transformations

“…The coupling reaction is suggested to occur through a Friedel‐Crafts type reaction. This approach has been recently expanded by using a tandem Friedel‐Crafts acylation/reductive alkylation of 4‐formylbenzoates with the same arene as the coupling partner (Scheme 26e) [70] …”

“…This approach has been recently expanded by using a tandem Friedel-Crafts acylation/reductive alkylation of 4-formylbenzoates with the same arene as the coupling partner (Scheme 26e). [70] Years before Xiao and Han's work, Das released a reductive bromination of aldehydes using bromodimethylsulfonium bromide (MeS + Br Br À ) and polymethylhydrosiloxane (PMHS) as the stoichiometric reductant (Scheme 27a). [71] This method tolerates both EDGs and EWGs (although it requires longer reaction times for the latter).…”