Convenient and Sustainable Reduction of β‐Nitrostyrenes

ABSTRACT

Phenethylamines are ubiquitous scaffolds in medicinal chemistry, yet traditional synthetic access via nitrostyrene reduction often relies on hazardous reagents, expensive catalysts, or operationally complex procedures. In this study, we describe a convenient and sustainable Zn/HCl‐mediated reduction of β‐nitrostyrenes to access functionally diverse phenethylamines. Utilizing greener solvents and implementing a continuous extraction protocol, this method effectively circumvents the persistent emulsion and product isolation bottlenecks typically caused by insoluble zinc byproducts. The optimized conditions exhibit broad substrate scope, reducing electron‐rich, electron‐deficient, and halogenated aryl substrates in high yields on scales up to 20 mmol. Notably, this methodology prevents overreduction of aryl bromides and nitriles. Furthermore, we identify that increasing substrate solubility appears to favor competing pathways that lead to the formation of cis ‐ and trans ‐3,4‐diphenylpyrrolidines. While limitations remain for isolating highly water‐soluble or zwitterionic substrates, this refined protocol offers a safe, robust, and economically viable procedure for the gram‐scale synthesis of β‐phenethylamines.