Allylic Amides Research Articles

ChemInform Abstract: Copper‐Catalyzed Intramolecular Electrophilic Carbofunctionalization of Allylic Amides.

AbstractThis intramolecular, endo‐selective oxyarylation and oxyvinylation of allylic amides affords highly functionalized oxazine derivatives.

Autotandem Catalysis with Ruthenium: Remote Hydroesterification of Allylic Amides

A one-pot tandem sequence involving olefin isomerization and hydroesterification has been developed that enables the incorporation of a C1-unit at the remote terminal position of allylic amides. Key observations suggest that generation of an active ruthenium hydride, formed by addition of acetic acid, allows both processes to take place under mild conditions in an autotandem catalytic, cascading fashion, which is characterized by the use of a single catalytic entity capable of promoting multiple distinct steps without operator intervention.

Ruthenium Hydride/Brønsted Acid-Catalyzed Tandem Isomerization/N-Acyliminium Cyclization Sequence for the Synthesis of Tetrahydro-β-carbolines

This paper describes an efficient tandem sequence for the synthesis of 1,2,3,4-tetrahydro-β-carbolines (THBCs) relying on a ruthenium hydride/Brønsted acid-catalyzed isomerization of allylic amides to N-acyliminium ion intermediates which are trapped by a tethered indole nucleophile. The methodology provides not only a convenient "aldehyde-free" alternative to the classical Pictet-Spengler reaction but also attractive possibilities for total synthesis, including rapid generation of molecular complexity and formation of quaternary stereogenic centers. TBHCs can also be accessed by harnessing the Suzuki cross-coupling reaction to the isomerization/N-acyliminium cyclization sequence. Finally, diastereo- and enantioselective versions of the title reaction have been examined using substrate control (with dr >15: 1) and asymmetric catalysis (ee up to 57%), respectively.

Construction of Spiro-Fused 2-Oxindole/α-Methylene- γ-Butyrolactone Systems with Extremely High Enantioselectivity via Indium-Catalyzed Amide Allylation of N-Methyl Isatin

A remarkably effective method allowing an extremely high enantioselective synthesis of the spiro-fused 2-oxindole/α-methylene-γ-butyrolactones is described. The key strategy lies in the use of indium-catalyzed asymmetric amide allylation of N-methyl isatin with functionalized allylstannanes, which can lead to the antineoplastic spirocyclic lactones in almost enantiopure forms.

ChemInform Abstract: Asymmetric Auto‐Tandem Catalysis with a Planar‐Chiral Ruthenium Complex: Sequential Allylic Amidation and Atom‐Transfer Radical Cyclization.

AbstractThe reaction of allylic chlorides with amides includes the use of CPR as the catalyst.

Copper‐Catalyzed Intramolecular Electrophilic Carbofunctionalization of Allylic Amides

This intramolecular, endo-selective oxyarylation and oxyvinylation of allylic amides affords highly functionalized oxazine derivatives.

Ruthenium-Catalyzed Asymmetric Allylic Amidation and Radical Cyclization

Ruthenium-Catalyzed Asymmetric Allylic Amidation and Radical Cyclization

ChemInform Abstract: Concise Asymmetric Synthesis of Orthogonally Protected syn‐ and anti‐1,3‐Aminoalcohols.

AbstractThe reaction of aldehydes (II) with novel chiral allylation reagent (I) leads to allyl carbonates (III), which are converted into orthogonally protected anti‐aminoalcohols (V) by an iridium‐catalyzed allylic amidation.

Asymmetric Auto‐Tandem Catalysis with a Planar‐Chiral Ruthenium Complex: Sequential Allylic Amidation and Atom‐Transfer Radical Cyclization

Ru does it all: A novel example of an asymmetric auto-tandem reaction catalyzed by a planar-chiral cyclopentadienyl–ruthenium complex is described. The reaction of allylic chloride with α-haloamides provides synthetically useful, diastereomerically and enantiomerically enriched γ-lactams with multiple stereogenic centers through one-pot sequential allylic amidation/atom-transfer radical cyclization. PG=protecting group.

Concise Asymmetric Synthesis of Orthogonally Protected syn- and anti-1,3-Aminoalcohols

Novel chiral binfunctional reagents V and ent-V undergo asymmetric aldehyde allylation followed by Ir(I)-catalyzed enantioselective allylic amidation to give orthogonally protected syn- and anti-1,3-aminoalcohols with complete control of absolute and relative stereochemistry. The Mitsunobu reaction of the initial homoallylic alcohol products followed by Ir(I)-catalyzed enantioselective allylic amidation provides orthogonally protected syn- and anti-1,3-diamine derivatives in high yields and with excellent stereoselectivities.

Multifaceted catalysis approach to nitrile activation: direct synthesis of halogenated allyl amides from allylic alcohols

Allyl amides were synthesised from the reaction of allyl alcohols and halogenated nitriles using a platinum multifaceted catalysis approach in which both the nucleophilic addition and subsequent [3,3]-sigmatropic rearrangement steps of the process were catalysed by the same complex. Additionally, (1)H/(13)C{(1)H} NMR and GC studies provided the first insights into the mechanism of this transformation.

Enantioselective synthesis of almorexant via iridium-catalysed intramolecular allylic amidation

An enantioselective synthesis of almorexant, a potent antagonist of human orexin receptors, is presented. The chiral tetrahydroisoquinoline core structure was prepared via iridium-catalysed asymmetric intramolecular allylic amidation. Further key catalytic steps of the synthesis include an oxidative Heck reaction at room temperature and a hydrazine-mediated organocatalysed reduction.

ChemInform Abstract: Mild and Efficient Allylation of Indoles and Amides Using Amberlyst‐15 as a Recyclable Heterogeneous Catalyst.

AbstractThe catalyst can be recycled and reused for at least seven runs without significant loss of activity.

Synthesis and antimicrobial activity of amide derivatives of polyether antibiotic—salinomycin

For the first time a direct and practical approach to the synthesis of eight amide derivatives of polyether antibiotic—salinomycin is described. The structure of allyl amide (3a) has been determined using X-ray diffraction. Salinomycin and its amide derivatives have been screened for their in vitro antimicrobial activity against the typical Gram-positive cocci, Gram-negative rods and yeast-like organisms, as well as against a series of clinical isolates of methicillin-resistant Staphylococcus aureus and methicillin-sensitive S. aureus. Amides of salinomycin have been found to show a wide range of activities, from inactive at 256μg/mL to active with MIC of 2μg/mL, comparable with salinomycin. As a result, phenyl amide (3b) was found to be the most active salinomycin derivative against Gram-positive bacteria, MRSA and MSSA.

Mild and Efficient Allylation of Indoles and Amides Using Amberlyst-15 as a Recyclable Heterogeneous Catalyst

A mild and efficient allylation of indoles and amides in the presence of a catalytic amount of Amberlyst-15 has been described in this context. The recyclable heterogeneous catalytic system is practical and facile for the synthesis of C- and N-allylated derivatives and would be of importance for the development of the accordingly functional complex molecules.

Synthetic Approaches to Highly Functional β-Carboline Building Blocks via Allylic Amidation

A new, straightforward synthesis of highly functional β-carboline building blocks is presented that makes use of allylic amidation methodology. The products obtained carry a terminal double bond as well as an easy-to-deprotect amide, which make them perfectly suitable for further functionalization. The use of the trifluoroacetamide group is exploited in a dual fashion; it acts as a protecting group and functions as the nucleophile for the allylic amidation reaction.

ChemInform Abstract: Intramolecular Palladium‐Catalyzed Aminocarboxylation of Olefins as a Direct Route to Bicyclic Oxazolidinones.

AbstractOxazolidinones fused to pyrazine or morpholine rings are prepared via aminocarboxylation reaction of allyl amides of N‐alkoxycarbonyl‐protected α‐amino acids in the presence of stoichiometric CuCl2.

Copper-Catalyzed Aerobic Oxidation of Hydroxamic Acids Leads to a Mild and Versatile Acylnitroso Ene Reaction

A mild formation of transient acylnitroso intermediates using a copper chloride catalyst and 1 atm of air as the terminal oxidant is described. The mild reaction conditions enable the inter- and intramolecular acylnitroso ene reaction with a wide range of functionalized alkene partners, as well as the first asymmetric variant. Notably, this transformation provides a practical and operationally simple method for effecting allylic amidation using an environmentally benign oxidant and a readily abundant transition metal.

CatalyticZ-Selective Olefin Cross-Metathesis

Selective formation of Z-disubstituted alkenes is an important synthetic problem, which is nonetheless poorly explored. In this ­paper, the authors developed molybdenum-­mediated scalable Z-selective cross-metathesis protocols, involving terminal enol ethers (never ­reported in cross-metathesis so far) and allylic amides (previously known to provide E-selectivity only). The synthetic utility of the developed methodologies was exemplified by implementation thereof in the total syntheses of biologically im­portant products C18 (plasm)-16:0 (PC) and KRN7000. The paper provides detailed considerations of mechanistic details and methodological challenges associated with them.

ChemInform Abstract: Iridium‐Catalyzed Asymmetric Intramolecular Allylic Amidation: Enantioselective Synthesis of Chiral Tetrahydroisoquinolines and Saturated Nitrogen Heterocycles.

AbstractAn iridium catalyst is used for the first time for the synthesis of chiral tetrahydroisoquinolines.