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DOI: 10.1055/s-0041-1738040
The Enantioselective Overman Rearrangement
Catalytic Asymmetric Rearrangement of Allylic Trichloroacetamidates. A Practical Method for Preparing Allylic Amines and Congeners of High Enantiomeric Purity.
J. Am. Chem. Soc. 2003;
125: 12412-12413
DOI: 10.1021/ja037086r.
Key words
allylic alcohols - allylic amines - acetamidates - palladium catalysis - [3+3]-sigmatropic rearrangementSignificance
Although first reported in 1974 (J. Am. Chem. Soc. 1974, 96, 597), an enantioselective variant of the Overman rearrangement remained challenging for the following decades. Competing elimination reactions, slow reaction rates, and low enantioselectivities were overcome by using the dimeric palladium catalyst COP-Cl. Starting from allylic alcohols, allylic amides are accessible in two steps with a formal [3+3]-sigmatropic rearrangement as the key step.
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Comment
High enantioselectivities and yields were observed throughout. Only sterically demanding substituents and aryl groups revealed the limitation of this protocol. The potential of this method was further demonstrated by derivatization of the obtained allylic amides, e.g., providing unnatural amino acids in only a few steps. Aside from palladium, mercury-, platinum- and gold-based catalysts have also been disclosed (for a review, see: Org. Biomol. Chem. 2017, 15, 2672).
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Publication History
Article published online:
20 April 2022
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