Brpnsted base/acid catalysis organocatalysis

This reaction encompasses a number of interesting features (general Brpnsted acid/ Brpnsted base catalysis, bifunctional catalysis, enantioselective organocatalysis, very short hydrogen bonds, similarity to serine protease mechanism, oxyanion hole), and we were able to obtain a complete set of DFT based data for the entire reaction path, from the starting catalyst-substrate complex to the product complex. 

During the last years, organocatalytic asymmetric aza-Michael additions have been thoroughly investigated [62, 63] employing different types of organocatalysis (amine, Brpnsted base, Brpnsted acid, PTC, and enzymatic catalysis). 

Asymmetric hydride reduction using Hantzsch ester has recently been extensively explored in organocatalysis using iminium-based catalysts or Brpnsted acid catalysts [72a-c], As an advance to their asymmetric conterion-directed catalysis (ACDC), List and coworkers found that the combination of simple primary amino acids such as L-valine with a chiral phosphoric acid led to an effective primary aminocatalyst for asymmetric transfer hydrogenation of a,P-unsaturated ketones (Scheme 5.43) [72d]. The catalysis could be applied to a range of substrates with good yields and excellent enantioselectivity. 

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