Morpholine Ketene Aminal as Amide Enolate Surrogate in Iridium‐Catalyzed Asymmetric Allylic Alkylation

Abstract

Morpholine ketene aminal is employed in iridiumcatalyzedasymmetric allylic alkylation reactions as asurrogate for amide enolates to prepare g,d-unsaturated b-substituted morpholine amides.Kinetic resolution or,alternatively,stereospecific substitution affords the corresponding products in high enantiomeric excess.T he utility of the products generated by this method has been showcased by their further elaboration into amines,k etones,o ra cyl silanes.Ap utative catalytic intermediate (h 3 -allyl)iridium(III) with achiral P, Olefin-ligand was synthetized and characterized for the first time.Supportinginformation and the ORCID identification number(s) for the author(s) of this article can be found under: https://doi.

Iridium/Acid Dual-Catalyzed Enantioselective Aza-ene-type Allylic Alkylation of Nitro Ketene Aminals with Racemic Allylic Alcohols

“…9,10 In 2019, Carreira and coworkers developed morpholine ketene aminal as a surrogate for amide enolates in Ir-catalyzed asymmetric allylic alkylations (Scheme 1a), affording γ,δ-unsaturated β-substituted morpholine amides with excellent enantioselectivities. 11,12 Inspired by this elegant work, as well as in conjunction with our continuing interest in the Ir-catalyzed asymmetric allylic alkylations, 13 we envisaged that nitro ketene aminal could serve as a valid nucleophilic reagent to trap electrophilic π-allyl-Ir species (Scheme 1b), and introducing the nitro group could inhibit the hydrolysis of ketene aminal, thus synthesizing α-allylic nitro ketene aminal derivatives. While this reaction design is theoretically feasible, there are still several inherent challenges.…”

Halogen Bond Motifs in Cocrystals of N,N,O and N,O,O Acceptors Derived from Diketones and Containing a Morpholine or Piperazine Moiety

“…Searching the Cambridge Structural Database, one can find a small number of larger, relatively bulky building blocks that are halogen bonded via either the morpholine oxygen or piperazine nitrogen atoms. Most numerous are polyfunctional organic compounds, − followed by metal–organic complexes ,− and clathrates. , Only a few of these studies ,,,− have been systematically focused on halogen bonding. Therefore, we set out to further investigate the possibility of halogen bond formation and the possible diversity of halogen bond motifs in bulkier molecules containing peripherally located morpholine and piperazine fragments as potential building blocks in the design of novel halogen-bonded multicomponent solids …”

Iridium-Catalyzed Asymmetric α-Allylic Alkylation of Amides using Vinyl Azide as Amide Enolate Surrogate

“…In 2019, Carreira and co-workers came up with an ingenious solution to this problem by using morpholine ketene aminal as the amide enolate equivalent to develop the first catalytic enantioselective formal allylic alkylation of α-unsubstituted acetamides (Scheme 1B). 8 Using branched allylic carbonates as the allylic electrophile, this reaction proceeds with kinetic resolution and gives rise to α-allyl tertiary amides with excellent enantioselectivity.…”