1111644-45-1

Upstream product

• 115-22-0 3-Hydroxy-3-methyl-2-butanone 
• 1122-91-4 4-bromo-benzaldehyde 

Downstream Products

• 1334529-05-3 methyl 4-(4-bromophenyl)-2-methyl-6-oxo-1,4,5,6-tetrahydropyridine-3-carboxylate 
• 1187092-71-2 N-benzyl-3-(4-bromophenyl)propanamide 

Relevant academic research and scientific papers

Enantioselective construction of tetrasubstituted stereogenic carbons through bronsted base catalyzed michael reactions: α′-hydroxy enones as key enoate equivalent

Catalytic and asymmetric Michael reactions constitute very powerful tools for the construction of new C-C bonds in synthesis, but most of the reports claiming high selectivity are limited to some specific combinations of nucleophile/electrophile compound types, and only few successful methods deal with the generation of all-carbon quaternary stereocenters. A contribution to solve this gap is presented here based on chiral bifunctional Bronsted base (BB) catalysis and the use of α′-oxy enones as enabling Michael acceptors with ambivalent H-bond acceptor/donor character, a yet unreported design element for bidentate enoate equivalents. It is found that the Michael addition of a range of enolizable carbonyl compounds that have previously demonstrated challenging (i.e., α-substituted 2-oxindoles, cyanoesters, oxazolones, thiazolones, and azlactones) to α′-oxy enones can afford the corresponding tetrasubstituted carbon stereocenters in high diastereo- and enantioselectivity in the presence of standard BB catalysts. Experiments show that the α′-oxy ketone moiety plays a key role in the above realizations, as parallel reactions under identical conditions but using the parent α,β-unsaturated ketones or esters instead proceed sluggish and/or with poor stereoselectivity. A series of trivial chemical manipulations of the ketol moiety in adducts can produce the corresponding carboxy, aldehyde, and ketone compounds under very mild conditions, giving access to a variety of enantioenriched densely functionalized building blocks containing a fully substituted carbon stereocenter. A computational investigation to rationalize the mode of substrate activation and the reaction stereochemistry is also provided, and the proposed models are compared with related systems in the literature.

α′-Hydroxyenones as mechanistic probes and scope-expanding surrogates for α,β-unsaturated aldehydes in N-heterocyclic carbene-catalyzed reactions

N-heterocyclic carbene-catalyzed reactions of α,β-unsaturatedaldehydes and a variety of electrophiles allow the facile preparation o f a diverse array of annulation products including trisubstituted cyclopentenes, γ-lactams, and bicyclic β-lactams. The substrate scope of these reactions, however, is limited by the difficulties of preparing the starting α,β-unsaturated aldehydes. We now report that α′- hydroxyenones, which can be prepared in a single convenient step from aromatic and heteroaromatic aldehydes, can serve as efficient surrogates for enals in the annulation reactions. This protocol allows the facile preparation and use of substrates bearing nitrogen heterocycles. These reagents have also allowed us to demonstrate that, in contrast to other classes of aldehydes, the formation of the Breslow intermediate from enals and N-heterocyclic carbenes is irreversible under the reaction conditions.

Catalytic amide formation with α′-hydroxyenones as acylating reagents

α′-Hydroxyenones undergo clean, catalytic amidations with amines promoted by the combination of an N-heterocyclic carbene and 1,2,4-triazole. The Royal Society of Chemistry 2009.