- Hydride reduction of alpha, beta-unsaturated carbonyl compounds using chiral organic catalysts
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Nonmetallic, chiral organic catalysts are used to catalyze the 1,4-hydride reduction of an α,β-unsaturated carbonyl compound. The α,β-unsaturated carbonyl compound may be an aldehyde or cyclic ketone, and the hydride donor may be a dihydropyridine. The reaction is enantioselective, and proceeds with a variety of hydride donors, catalysts, and substrates. The invention also provides compositions effective in carrying out the 1,4-hydride addition of α,β-unsaturated carbonyl compounds.
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Page/Page column 12-13
(2008/06/13)
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- Enantioselective organocatalytic hydride reduction
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The first enantioselective organocatalytic hydride reduction has been accomplished. The use of iminium catalysis has provided a new organocatalytic strategy for the enantioselective reduction of β,β-substituted αβ-unsaturated aldehydes to generate β-stereogenic aldehydes. The use of imidazolidinone 2 as the asymmetric catalyst has been found to mediate the transfer of hydrogen to a large class of enal substrates from ethyl Hantzsch ester. The capacity of catalyst 2 to accelerate E-Z isomerization prior to selective E-olefin reduction allows the implementation of geometrically impure enals in this operationally simple protocol. Copyright
- Ouellet, Stephane G.,Tuttle, Jamison B.,MacMillan, David W. C.
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