Issue Date: February 1, 2016
Iron Catalysts For Enantioselective Hydrogenations
Making chiral alcohols and amines via enantioselective hydrogenation of ketones and imines is a cinch for chemists. But the ruthenium, iridium, and rhodium catalysts usually used for such transformations are expensive and toxic, which makes them unattractive for industrial applications. Because many pharmaceuticals, agrochemicals, flavors, and fragrances feature alcohols or amines with a stereogenic carbon at the α-position, chemists have been developing inexpensive, nontoxic iron catalysts capable of doing the same reaction. Until now, however, they haven’t managed to compete with the yields and enantioselectivity of the platinum-group metals. Antonio Mezzetti and Raphael Bigler of ETH Zurich report two iron catalysts (shown) that hydrogenate polar double bonds to produce chiral alcohols and amines with up to 99.7% yield and 99.4% enantioselectivity (Org. Process Res. Dev. 2016, DOI: 10.1021/acs.oprd.5b00391). This suggests that it’s possible to swap precious-metal catalysts for iron catalysts without sacrificing yield or enantioselectivity.
- Chemical & Engineering News
- ISSN 0009-2347
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