Stereoselective Synthesis of α-Alkyl-β-keto Imides via Asymmetric Redox C−C Bond Formation between α-Alkyl-α-diazocarbonyl Compounds and Aldehydes

Abstract

Asymmetric redox C-C bond formation between alpha-alkyl-alpha-diazocarbonyl compounds and aldehydes was developed as a practical and general method for the construction of alpha-alkyl-beta-keto imides having a chiral nonracemic tertiary stereogenic center.

Metal‐Free Geminal Difunctionalization of Diazocarbonyl Compounds: A One‐Pot Multicomponent Strategy for the Construction of α,β‐Diamino Carbonyl Derivatives

“…Next, we focused on the development of an asymmetric variant of this unprecedented three‐component reaction. As a large number of chiral auxiliaries can be introduced at the ester moiety of α‐diazo compounds, asymmetric induction of central chirality during our multicomponent reactions of α‐diazocarbonyl compounds might be also anticipated . Chiral auxiliaries of α‐diazocarbonyl compounds have been detected in our system.…”

Development of Synthetic Transformations by Control of Acid-Catalyzed Reactions of Diazocarbonyl Compounds

“…In this case, the CH bond of the aldehyde migrated preferentially to give α-alkyl-β-ketocarbonyl compounds 13 stereoselectively (Scheme 12). 17 This reaction is considered to be an asymmetric variant of the Roskamp reaction. 18 The only precedent report which provides similar compounds in an asymmetric manner is the Evans's asymmetric Claisen condensation.…”

“…Ring expansion of 4-silyloxy-and 4-alkoxysubstituted cyclohexanones. 2013)metric Roskamp reaction, 17 the stereogenic center at the α-position resists epimerization.…”

“…A clue to tap into this unexplored field was provided in the study on the application of diazocarbonyl compounds bearing camphorsultam 12. 17 We applied these diazocarbonyl compounds in the reaction of N-Boc imines which resulted in the stereoselective formation of trisubstituted trans-aziridines 43 (Scheme 33). 36 An important finding in this research is the necessity to use diazocarbonyl compounds bearing a sultam or an oxazolidinone which paved the way to realize catalytic asymmetric reaction (Scheme 34).…”

Palladium‐Catalyzed Intermolecular Acylation of Aryl Diazoesters with ortho‐Bromobenzaldehydes

“…To the best of our knowledge,the activation of aC(sp 2 ) À Hbond of an aldehyde moiety via ac arbene approach has previously never been reported. [11,12] To validate our hypothesis,w ei nitially investigated the stoichiometric reaction of palladium complex A [13] with ethyl diazophenylacetate (2a)inthe presence of K 3 PO 4 at 60 8 8Cin N,N-dimethylformamide (DMF). To our surprise,i socoumarin 4aa was isolated in 28 %y ield.…”