Mechanochemical Organocatalysis: Do High Enantioselectivities Contradict What We Might Expect?

Abstract

Ball mills input energy to samples by pulverising the contents of the jar. Each impact on the sample or wall of the jar results in an instantaneous transmission of energy in the form of a temperature and pressure increase (volume reduction). Conversely, enantioselective organocatalytic reactions proceed through perceived delicate and well‐organised transition states. Does there exist a dichotomy in the idea of enantioselective mechanochemical organocatalysis? This Review provides a survey of the literature reporting the combination of organocatalytic reactions with mechanochemical ball milling conditions. Where possible, direct comparisons of stirred in solution, stirred neat and ball milled processes are drawn with a particular focus on control of stereoselectivity.

Disentangling the Effect of Pressure and Mixing on a Mechanochemical Bromination Reaction by Solid‐State NMR Spectroscopy**

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Assessing the Greenness of Mechanochemical Processes with the DOZN 2.0 Tool

“…There are accelerating approaches to reduce the environmental footprint for manufacturing processes, operations, and products. Mechanochemistry is being actively developed and finds uses in various fields of chemistry (e.g., organic synthesis, − metal catalysis, enzymatic catalysis, organocatalysis, main group chemistry, and accessing new pharmaceutical solid forms). Mechanochemical processes complement the green chemistry toolbox, providing a paradigm shift and an alternative approach on the way that chemical transformations are conducted.…”

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