Allylic Amination Reaction Research Articles

Silicon-directed rhenium-catalyzed allylic substitutions with N-hydroxycarbamates, N-hydroxysulfonamides, and hydroxamic acids.

A rhenium-catalyzed N-selective allylic amination reaction of N-hydroxycarbamates has been developed. This reaction occurs with excellent N/O selectivity and with complete carbon selectivity on the allylic system. The reaction is tolerant of many functional groups and also proceeds with N-hydroxysulfonamides and hydroxamic acids.

Synthesis of Thioalkyne-Substituted Thiazolidine-2-thiones Using Tris(tri­methylsilyl)methyllithium and Carbon Disulfide

An efficient, environmentally benign, and simple one-pot approach to the synthesis of 5-(iodomethyl)thiazolidine-2-thiones via multicomponent reaction of allylamines, carbon disulfide, and iodine under solvent-free conditions is presented. The obtained 5-(iodomethyl)thiazolidine-2-thiones were converted into silyl-protected­ terminal [(ethynylthio)methyl]-substituted thiazolidine-2-thiones by treatment with lithium 2,2,2-tris(trimethylsilyl)ethanedithioate, produced by the reaction of tris(trimethylsilyl)methyllithium with carbon disulfide.

Synthesis, characterization and X-ray crystal structures of Vanadium(IV), Cobalt(III), Copper(II) and Zinc(II) complexes derived from an asymmetric bidentate Schiff-base ligand at ambient temperature

An asymmetric bidentate Schiff-base ligand (HL: 2-((allylimino)methyl)phenol) was prepared from reaction of salicylaldehyde and Allylamine. Vanadium(IV), Cobalt(III), Copper(II) and Zinc(II) complexes, VOL2, CoL3, CuL2 and ZnL2 were synthesized from the reaction of VO(acac)2, CoCl2·6H2O, CuCl2·2H2O and Zn(NO3)2·6H2O with the bidentate Schiff base ligand (HL: 2-allyliminomethyl-phenol) in methanol at ambient temperature. The ligand and its metal complexes were characterized by elemental analysis (CHN), FT-IR spectroscopy. In addition, 1H and 13C NMR techniques were employed for characterization of the ligand (HL) and diamagnetic complex ZnL2. The molecular structures of all complexes were determined by single crystal X-ray diffraction technique. In the ZnL2 and CuL2 complexes, the metal ion is coordinated by two nitrogen and two oxygen atoms from two Schiff base ligands in an approximately square planar trans-[MN2O2] coordination geometry. In the Vanadium(IV) complex, VOL2, the vanadium center in this structure has a distorted tetragonal pyramidal N2O3 coordination sphere and for Cobalt(III) complex, CoL3, the CoIII ion is six coordinated by three bidentate Schiff base ligands in a distorted octahedral environment.

First evidence for the use of polyamines as nucleophiles in a regioselective palladium-catalyzed allylic amination reaction

Palladium-catalyzed reaction of unsymmetrical allylic electrophiles with polyamines gives rise to regioisomeric allylic polyamines. An original catalytic procedure providing an efficient method for the regioselective synthesis of new classes of polyamino derivatives of biological interest is reported. Based on experimental considerations, a mechanistic rationale involving a thermodynamically controlled isomerization of the initially formed branched product is proposed to account for the total regioselectivity observed.

New MCR based on intramolecular Heck reaction under aerobic conditions: a direct access to cytotoxic fused N-heterocycles

We report a new MCR involving the reaction of isatoic anhydrides, allyl amine and o-bromo arylaldehydes in the presence of Pd(OAc)2, X-Phos and air to afford various isoquinolino[1,2-b]quinazolinones as new cytotoxic agents. The strategy was extended successfully towards the synthesis of a methyl analogue of 7,8-dehydrorutaecarpine.

Total synthesis of alkaloid 205B.

Concise and highly stereocontrolled total syntheses of racemic and enantiopure frog alkaloid 205B (1) were accomplished in 11 steps from 4-methoxypyridines 6 and 7 in overall yields of 8 and 8%, respectively. The assembly of the core of the natural product relies on a stereoselective Tsuji–Trost allylic amination reaction and a ring-closing metathesis. The synthesis features the use of an N-acylpyridinium salt reaction to introduce the first stereocenter and an unprecedented trifluoroacetic anhydride-mediated addition of an allylstannane to a vinylogous amide with complete facial selectivity. Deoxygenation of the C4 ketone proved difficult but was accomplished via a modified Barton–McCombie reaction in the presence of a catalytic amount of diphenyl diselenide.

ChemInform Abstract: Highly Versatile Pd—Thioether—Phosphite Catalytic Systems for Asymmetric Allylic Alkylation, Amination, and Etherification Reactions.

AbstractA series of furanoside thioether‐phosphite ligands is synthesized and their Pd‐complexes are used as efficient catalyst for the asymmetric allylic substitution of a variety of cyclic and noncyclic allylic acetates and carbonates with C‐, N‐, and O‐nucleophiles.

ChemInform Abstract: Rhodium‐Catalyzed Sequential Allylic Amination and Olefin Hydroacylation Reactions: Enantioselective Synthesis of Seven‐Membered Nitrogen Heterocycles.

AbstractThe cyclization of the alkenals occurs without razemization.

ChemInform Abstract: Regio‐ and Enantioselective Synthesis of N‐Allylindoles by Iridium‐Catalyzed Allylic Amination/Transition‐Metal‐Catalyzed Cyclization Reactions.

AbstractThe title reaction is realized through an iridium‐catalyzed asymmetric allylic amination reaction with various alkynylanilines and subsequent cyclization.

ChemInform Abstract: Oxidative Allylic Amination Reactions of Unactivated Olefins — At the Frontiers of Palladium and Selenium Catalysis

AbstractReview: [27 refs.

ChemInform Abstract: Enantioselective Synthesis of Planar Chiral Ferrocenes via Pd(0)‐Catalyzed Intramolecular Direct C—H Bond Arylation.

A highly efficient synthesis of planar chiral ferrocenes by enantioselective Pd(0)-catalyzed direct C–H arylation from readily available starting materials under mild reaction conditions was developed (up to 99% yield, 99% ee). The products can be easily transformed to the highly efficient planar ferrocene ligands, which have demonstrated high efficiency in Pd-catalyzed asymmetric allylic alkylation and amination reactions.

Direct asymmetric dearomatization of pyridines and pyrazines by iridium-catalyzed allylic amination reactions.

The first iridium-catalyzed intramolecular asymmetric allylic dearomatization reaction of pyridines and pyrazines has been realized. 2,3-Dihydroindolizine and 6,7-dihydropyrrolo[1,2-a]pyrazine derivatives were obtained with excellent yields and enantioselectivity. This methodology features dearomatization by direct N-allylic alkylation of pyridines or pyrazines under mild reaction conditions.

Direct Asymmetric Dearomatization of Pyridines and Pyrazines by Iridium‐Catalyzed Allylic Amination Reactions

AbstractThe first iridium‐catalyzed intramolecular asymmetric allylic dearomatization reaction of pyridines and pyrazines has been realized. 2,3‐Dihydroindolizine and 6,7‐dihydropyrrolo[1,2‐a]pyrazine derivatives were obtained with excellent yields and enantioselectivity. This methodology features dearomatization by direct N‐allylic alkylation of pyridines or pyrazines under mild reaction conditions.

Highly Versatile Pd–Thioether–Phosphite Catalytic Systems for Asymmetric Allylic Alkylation, Amination, and Etherification Reactions

A Pd-furanoside thioether-phosphite catalytic system that can create new C-C, C-N, and C-O bonds in several substrate types using a wide range of nucleophiles in high yields and enantioselectivities has been identified. Of particular note are the excellent enantioselectivities obtained in the etherification of linear and cyclic substrates. The potential application of the new Pd-thioether-phosphite catalytic systems was also demonstrated by the synthesis of the chiral carbo- and heterocycles.

Enantioselective Synthesis of Planar Chiral Ferrocenes via Pd(0)-Catalyzed Intramolecular Direct C–H Bond Arylation

A highly efficient synthesis of planar chiral ferrocenes by enantioselective Pd(0)-catalyzed direct C-H arylation from readily available starting materials under mild reaction conditions was developed (up to 99% yield, 99% ee). The products can be easily transformed to the highly efficient planar ferrocene ligands, which have demonstrated high efficiency in Pd-catalyzed asymmetric allylic alkylation and amination reactions.

ChemInform Abstract: N‐Bromoimide/DBU Combination as a New Strategy for Intermolecular Allylic Amination.

Allylic amination reactions of alkenes, with an NBP (N-bromophthalimide) or NBS (N-bromosuccinimide)/DBU combination, were developed, in which both internal and external nitrogen nucleophiles can be installed directly. Dual activation of NBS or NBP by DBU leads to more electrophilic bromine and more nucleophilic nitrogen atoms simultaneously. This protocol may provide a novel and complementary access to allylic amination under mild conditions.

Rhodium‐Catalyzed Sequential Allylic Amination and Olefin Hydroacylation Reactions: Enantioselective Synthesis of Seven‐Membered Nitrogen Heterocycles

Dynamic kinetic asymmetric amination of branched allylic acetimidates has been applied to the synthesis of 2-alkyl-dihydrobenzoazepin-5-ones. These seven-membered-ring aza ketones are prepared in good yield with high enantiomeric excess by rhodium-catalyzed allylic substitution with 2-amino aryl aldehydes followed by intramolecular olefin hydroacylation of the resulting alkenals. This two-step procedure is amenable to varied functionality and proves useful for the enantioselective preparation of these ring systems.

Rhodium‐Catalyzed Sequential Allylic Amination and Olefin Hydroacylation Reactions: Enantioselective Synthesis of Seven‐Membered Nitrogen Heterocycles

AbstractDynamic kinetic asymmetric amination of branched allylic acetimidates has been applied to the synthesis of 2‐alkyl‐dihydrobenzoazepin‐5‐ones. These seven‐membered‐ring aza ketones are prepared in good yield with high enantiomeric excess by rhodium‐catalyzed allylic substitution with 2‐amino aryl aldehydes followed by intramolecular olefin hydroacylation of the resulting alkenals. This two‐step procedure is amenable to varied functionality and proves useful for the enantioselective preparation of these ring systems.

Regio‐ and Enantioselective Synthesis of N‐Allylindoles by Iridium‐Catalyzed Allylic Amination/Transition‐Metal‐Catalyzed Cyclization Reactions

Regio- and enantioselective synthesis of N-allylindoles was realized through an iridium-catalyzed asymmetric allylic amination reaction with 2-alkynylanilines and subsequent transition-metal-catalyzed cyclization reactions. The highly enantioenriched allylic amines prepared from Ir-catalysis were treated with catalytic amount of NaAuCl4⋅2 H2O or PdCl2 providing various substituted N-allylindoles in excellent yields and enantioselectivities.

Oxidative Allylic Amination Reactions of Unactivated Olefins – At the Frontiers of Palladium and Selenium Catalysis

The direct oxidative conversion of simple, nonactivated alkenes into allylic amine derivatives represents a profound challenge to contemporary chemical synthesis. This article provides an overview on recent methodological developments and applications in the realm of modern palladium- and selenium-catalyzed oxidative allylic amination reactions.