Few layer 2D pnictogens catalyze the alkylation of soft nucleophiles with esters

TL;DR

This paper introduces a novel method for synthesizing stable, few-layer 2D pnictogen catalysts that enable efficient alkylation of nucleophiles with esters under milder conditions, expanding their synthetic utility.

Contribution

The study reports the first synthesis of stable, exfoliated 2D pnictogens in zero oxidation state used as catalysts for ester-based alkylation, avoiding harsh conditions.

Findings

Efficient alkylation of various nucleophiles with esters using 2D pnictogen catalysts.

Protection from air and water enables stable, reusable catalysts.

Reactions proceed under milder conditions than traditional superacid catalysis.

Abstract

Group 15 elements in zero oxidation state (P, As, Sb and Bi), also called pnictogens, are rarely used in catalysis due to the difficulties associated in preparing well-structured and stable materials. Here, we report on the synthesis of highly exfoliated, few layer 2D phosphorene and antimonene in zero oxidation state, suspended in an ionic liquid, with the native atoms ready to interact with external reagents while avoiding aerobic or aqueous decomposition pathways, and on their use as efficient catalysts for the alkylation of nucleophiles with esters. The few layer pnictogen material circumvents the extremely harsh reaction conditions associated to previous superacid-catalyzed alkylations, by enabling an alternative mechanism on surface, protected from the water and air by the ionic liquid. These 2D catalysts allow the alkylation of a variety of acid-sensitive organic molecules and giving synthetic relevancy to the use of simple esters as alkylating agents.