Scalable Wolff–Kishner Reductions in Extreme Process Windows Using a Silicon Carbide Flow Reactor

Autor: Doris Dallinger, Anne O’Kearney-McMullan, Peter Poechlauer, Christoph Schmoelzer, Desiree Znidar, Charlotte Wiles, Rachel H. Munday, C. Oliver Kappe
Rok vydání: 2019
Předmět:
Zdroj: Organic Process Research & Development. 23:2445-2455
ISSN: 1520-586X
1083-6160
Popis: A safe and scalable continuous flow strategy for Wolff–Kishner reductions that employs methanol as the solvent has been developed. The use of low-cost hydrazine as the reducing agent in combination with a caustic base provides an atom-efficient, environmentally friendly method for the deoxygenation of aldehydes and ketones to alkanes. Because of the required harsh and corrosive reaction conditions (200 °C, 50 bar), reactor materials such as stainless steel, glass, or any type of polymer have compatibility problems, rendering this process problematic on a production scale. The use of corrosion-resistant silicon carbide (SiC) as the reactor material opens up the possibility of performing Wolff–Kishner reductions on scale with a considerably improved safety profile. Methanol as the solvent significantly simplifies the workup procedure compared with the generally employed high-boiling solvents such as diethylene glycol. The continuous flow protocol was applied to a number of substrates and provided the desire...
Databáze: OpenAIRE