Improved Methodology for the Preparation of Chiral Amines

hazardous substances. Green chemistry can be defined as the new trend in chemistry which
efficiently utilizes (preferably renewable) raw materials, eliminates waste and avoids the use
of toxic and/or hazardous reagents and solvents in the manufacture and application of
chemical products. [65]
Recently scientists proposed the basic principles of Green Chemistry which can be
paraphrased as: [65,66]
1. Waste prevention instead of disposal.
2. Atom efficiency and atom economy.
3. Less hazardous/toxic chemicals
4. Design safer process and safer product.
5. Safe solvents and auxiliaries
6. Design efficient energy manipulation.
7. Use of renewable raw materials.
8. Step wise efficient methodologies.
9. Catalytic rather than stoichiometric reagents
10. Biodegradable products.
11. Desing analytical techniques for pollution control.
12. Inherently safer working environment.
Green chemistry main concern is the environmental impact of both chemical products and the
processes by which they are produced. It is well known that prevention is better than cure.
Green chemistry eliminates waste at source, it focuses on primary pollution prevention rather
than waste remediation (end-of-pipe solutions).
To be able to classify any chemical or pharmaceutical process as green process, two
important measures of the potential environmental acceptability of the process have been
introduced the E factor and the Atom Efficiency. [65]
The E factor is defined as the mass ratio of the waste to the desired product. A higher E factor
means more waste and, consequently, greater negative environmental impact. The ideal E
factor is zero. It was found that the pharmaceutical industry has the highest E factor
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