High-speed Ball Milling Enables an Ultra-fast Wittig Olefination Under Ambient and Solvent-free Conditions Without Ylide Pre-formation

Abstract

30 Seconds to success! – The Wittig reaction, a fundamental and extensively utilized reaction in organic chemistry, enables the efficient conversion of carbonyl compounds to olefins using phosphonium salts. Traditionally, meticulous reaction setup, including the pre-formation of a reactive ylide species via deprotonation of a phosphonium salt, is crucial for achieving high-yielding reactions under classical solution-based conditions. In this report, we present an unprecedented protocol for an ultra-fast mechanochemically driven Wittig reaction under solvent-free and ambient conditions, eliminating the need for tedious ylide pre-formation under strict air and moisture exclusion. A range of aldehydes and ketones were reacted with diverse phosphonium salts under high-speed ball milling conditions, giving access to the respective olefins in only 30 seconds.