Showing papers on "Tsuji–Trost reaction published in 2014"
TL;DR: 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.
Abstract: 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.
166 citations
TL;DR: A computational study suggested that methanol plays a crucial role in the formation of the π-allylpalladium complex by lowering the activation barrier.
Abstract: Allylic alcohols were directly used in Pd-catalyzed allylic alkylations of simple ketones under mild reaction conditions. The reaction proceeded smoothly at 20 °C by the concerted action of a Pd catalyst, a pyrrolidine co-catalyst, and a hydrogen-bonding solvent, and does not require any additional reagents. A computational study suggested that methanol plays a crucial role in the formation of the π-allylpalladium complex by lowering the activation barrier.
136 citations
TL;DR: C-O bond cleavage of allylic alkyl ether was realized in a Pd-catalyzed hydrogen-bond-activated allylicAlkylation using only alcohol solvents and can be easily extended to the asymmetric synthesis of enantiopure products (99% ee).
90 citations
TL;DR: On the basis of the results of experiments using an isomeric secondary allylic phosphate, which gave a branched product through an α-selective substitution reaction with retention of configuration, a reaction pathway involving 1,3-allylic migration of Cu in a ([σ + π]-allyl)copper(III) species is proposed.
Abstract: The copper-catalyzed enantioselective allylic alkylation of terminal alkynes with primary allylic phosphates was developed by the use of a new chiral N-heterocyclic carbene ligand bearing a phenolic hydroxy group at the ortho position of one of the two N-aryl groups. This reaction occurred with excellent γ-branch regioselectivity and high enantioselectivity, forming a controlled stereogenic center at the allylic/propargylic position. Various terminal alkynes, including silyl, aliphatic, and aromatic alkynes, could be used directly without premetalation of the C(sp)–H bond. On the basis of the results of experiments using an isomeric secondary allylic phosphate, which gave a branched product through an α-selective substitution reaction with retention of configuration, a reaction pathway involving 1,3-allylic migration of Cu in a ([σ + π]-allyl)copper(III) species is proposed.
74 citations
TL;DR: This process demonstrates that unstabilized cyclic ketone enolates can undergo diastereo- and enantioselective Ir-catalyzed allylic substitution reactions with the proper choice of enolate countercation.
Abstract: We report asymmetric allylic alkylation of barium enolates of cyclic ketones catalyzed by a metallacyclic iridium complex containing a phosphoramidite ligand derived from (R)-1-(2-naphthyl)ethylamine. The reaction products contain adjacent quaternary and tertiary stereocenters. This process demonstrates that unstabilized cyclic ketone enolates can undergo diastereo- and enantioselective Ir-catalyzed allylic substitution reactions with the proper choice of enolate countercation. The products of these reactions can be conveniently transformed to various useful polycarbocyclic structures.
67 citations
TL;DR: Ferrocene and ruthenocene-based planar chiral ligands have been developed and used in transition-metal-catalyzed asymmetric allylic substitutions, asymmetric hydrogenations, and asymmetric conjugate addition reactions as mentioned in this paper.
Abstract: Ferrocene- and ruthenocene-based planar chiral ligands have been developed and used in transition-metal-catalyzed asymmetric allylic substitutions, asymmetric hydrogenations, and asymmetric conjugate addition reactions. The most common ferrocene ligands, which have bis(oxazoline) substituents on the cyclopentadiene rings, have been modified to create new planar chiral C
2-symmetric ligands, some of which have shown excellent potential in the aforementioned reactions. A series of planar chiral ruthenocene ligands have also been developed and their activities differ from those of their ferrocene counterparts. 1 Introduction 2 The Design and Synthesis of Planar Chiral Ligands 2.1 Ferrocene-Based Ligands 2.2 Ruthenocene-Based Ligands 3 Applications of Planar Chiral Ligands in Asymmetric Reactions 3.1 Asymmetric Allylic Alkylation 3.2 Asymmetric Allylic Amination 3.3 Asymmetric Allylic Alkylation with Enamines as Nucleophiles 3.4 Asymmetric Alkylation of Aryl Aldehydes 3.5 Asymmetric Hydrogenation 3.6 1,4-Asymmetric Conjugation Reactions 4 Summary
67 citations
TL;DR: By combining catalytic nucleophilic enamine activation with Pd-catalyzed C-H activation of allylarenes, the first oxidative allylic alkylation of unactivated ketones was achieved.
63 citations
TL;DR: The one-pot reaction involving a Cu(I)/Pd(0) cooperative dual catalyst directly addresses the need to develop more time-efficient and less-wasteful synthetic pathways.
Abstract: This paper describes a tunable and stereoselective dual catalytic system that uses copper and palladium reagents. This cooperative silylcupration and palladium-catalyzed allylation readily affords trisubstituted alkenylsilanes. Fine-tuning the reaction conditions allows selective access to one stereoisomer over the other. This new methodology tolerates different substituents on both coupling partners with high levels of stereoselectivity. The one-pot reaction involving a CuI/Pd0 cooperative dual catalyst directly addresses the need to develop more time-efficient and less-wasteful synthetic pathways. © 2014 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.
62 citations
TL;DR: Tetra-3-benzazepines and tetrahydroisoquinolines are synthesized in one step from allenes and phenylethylamines or benzylamines, respectively, and are particularly useful with 2,3-butadienoates and amines having a quaternary carbon at the α-position.
Abstract: Tetrahydro-3-benzazepines and tetrahydroisoquinolines are synthesized in one step from allenes and phenylethylamines or benzylamines, respectively. Mechanistically, it is assumed that activation of a C–H bond of an aromatic ring with Pd(II) occurs, directed by the primary amine, leading to the formation of a palladacycle into which an allene then undergoes insertion. The resulting π-allyl intermediate cyclizes to the products by an intramolecular allylic alkylation. The process is particularly useful with 2,3-butadienoates and amines having a quaternary carbon at the α-position.
59 citations
TL;DR: A serendipitously discovered palladium-catalyzed asymmetric allylic alkylation reaction with diorganozinc reagents, which displays broad functional group compatibility, is reported.
Abstract: A serendipitously discovered palladium-catalyzed asymmetric allylic alkylation reaction with diorganozinc reagents, which displays broad functional group compatibility, is reported. This novel transformation hinges on a remarkable ligand effect which overrides the standard "umpolung" reactivity of allyl-palladium intermediates in the presence of dialkylzincs. Owing to its mild conditions, enantioselective allylic alkylations of racemic allylic electrophiles are possible in the presence of sensitive functional groups.
54 citations
TL;DR: The first example of a Pd-catalyzed Tsuji-Trost reaction, applied in a photochromic micellar media under conventional heating and microwave irradiation, is reported and the surfactant activity and recycling ability were investigated and compared with a few commercially available surfactants.
Abstract: The first example of a Pd-catalyzed Tsuji-Trost reaction, applied in a photochromic micellar media under conventional heating and microwave irradiation, is reported. The surfactant activity and recycling ability were investigated and compared with those of a few commercially available surfactants. The synthetic photochromic surfactant proved to be efficient, recyclable, and versatile for Pd-catalyzed coupling reactions.
TL;DR: The first highly stereoselective organocatalytic intermolecular allylic alkylation of allylic alcohols with 1,3-dicarbonyls has been developed to allow the first enantioselectives total synthesis of hydroxymetasequirin-A and metasequirit-B tetramethyl ether diacetates.
TL;DR: The development of (trimethylsilyl)ethyl ester protected enolates and the application of this class of compounds in palladium-catalyzed asymmetric allylic alkylation is explored, yielding a variety of α-quaternary six- and seven-membered ketones and lactams.
TL;DR: A comprehensive account of the applications of mixed ligands featuring both a phosphine and an iminophosphorane moiety in homogeneous catalysis is presented in this paper, where metal-catalyzed hydrogenation and transfer hydrogenation reactions, C-C cross-couplings, olefin oligomerization and cyclopropanation processes, allylic alkylation and oxidation reactions, Meyer-Schuster rearrangements and cycloisomerization processes are discussed.
TL;DR: 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.
TL;DR: A Brønsted acid accelerated Pd-catalyzed asymmetric allylic alkylation of azlactones with simple allylic alcohols under mild reaction conditions has been realized, which provides a direct and readily scalable approach for the synthesis of all-carbon quaternary allylic amino acid derivatives in excellent yields and good enantioselectivities.
TL;DR: A palladium-catalyzed asymmetric decarboxylative allylic alkylation of allyl 2,2-diphenylglycinate imines using (S,S)-f-binaphane as a chiral supporting ligand has been developed.
TL;DR: A dual platinum- and pyrrolidine-catalyzed direct allylic alkylation of allylic alcohols with various active methylene compounds to produce products with high monoallylation selectivity was developed.
Abstract: A dual platinum- and pyrrolidine-catalyzed direct allylic alkylation of allylic alcohols with various active methylene compounds to produce products with high monoallylation selectivity was developed. The use of pyrrolidine and acetic acid was essential, not only for preventing undesirable side reactions, but also for obtaining high monoallylation selectivity.
TL;DR: The exploitation of this method in combinatorial ligand screening has enabled the rapid identification of the optimal ion-paired chiral ligand for the palladium-catalyzed asymmetric allylic alkylation of benzo[b]thiophen-2(3H)-ones.
Abstract: A method for the in situ generation of ion-paired chiral ligands from simple salts of ammonium phosphines and chiral Bronsted acids under phase-transfer conditions is established. The exploitation of this method in combinatorial ligand screening has enabled the rapid identification of the optimal ion-paired chiral ligand for the palladium-catalyzed asymmetric allylic alkylation of benzo[b]thiophen-2(3H)-ones.
TL;DR: This one-pot SN2' allylation-Wittig strategy constitutes a convenient and efficient synthetic method for highly functionalized skipped dienes from readily available starting materials.
Abstract: A catalyst-free allylic alkylation of stabilized phosphorus ylides with allylic carbonates via a regioselective SN2′ process is presented. Subsequent one-pot Wittig reaction with both aliphatic and aromatic aldehydes as well as ketenes provides structurally diverse skipped dienes (1,4-dienes) in generally high yields and moderate to excellent stereoselectivity with flexible substituent patterns. This one-pot SN2′ allylation–Wittig strategy constitutes a convenient and efficient synthetic method for highly functionalized skipped dienes from readily available starting materials.
TL;DR: The enantioselective synthesis of α- and γ-tocopherol (the most biologically active members of vitamin E family) and analogues has been accomplished employing a new enantiOSElective gold catalyzed intramolecular allylic alkylation reaction followed by an olefin cross-metathesis as key steps.
Abstract: The enantioselective synthesis of α- and γ-tocopherol (the most biologically active members of vitamin E family) and analogues has been accomplished employing a new enantioselective gold catalyzed intramolecular allylic alkylation reaction followed by an olefin cross-metathesis as key steps. The methodology proved to be applicable to different olefins highlighting its potential for the synthesis of diverse libraries.
TL;DR: A new type of chiral sulfoxide-phosphine ligands have been developed by a rational combination of two privileged scaffolds for Pd-catalyzed asymmetric allylic alkylation reactions under optimized conditions.
TL;DR: With this protocol, a catalytic asymmetric total synthesis of indolizidine (-)-209I was realized for the first time.
TL;DR: The first highly E- and enantioselective allylic alkylation of prochiral carbon nucleophiles with 1,2-disubstituted allylic carbonates with modular ion-paired chiral ligands is reported.
TL;DR: An efficient and practical method was developed for the synthesis of 2,2-disubstituted indolin-3-ones by palladium-catalyzed asymmetric allylic alkylation.
Abstract: An efficient and practical method was developed for the synthesis of 2,2-disubstituted indolin-3-ones by palladium-catalyzed asymmetric allylic alkylation. Enantioselective construction of quaternary carbon centers was also realized in this way.
TL;DR: The kinetic resolution of 4-substituted-3-4-dihydrocoumarins was realized via Pd-catalyzed allylic substitution reaction using Trost's chiral ligand L12, affording optically active mono- and trans-3,4-disubstituting dihydrocou marin derivatives in high yields and with high enantioselectivities with an S factor up to 55.
Abstract: The kinetic resolution of 4-substituted-3,4-dihydrocoumarins was realized via Pd-catalyzed allylic substitution reaction using Trost's chiral ligand L12, affording optically active mono- and trans-3,4-disubstituted dihydrocoumarin derivatives in high yields and with high enantioselectivities with an S factor up to 55.
TL;DR: This protocol provides a unique and facile access to prepare enantioenriched densely functionalized dihydronaphthoquinones accompanied by enantiomerically pure 3,3-disubstituted phthalides bearing quaternary carbon centers.
TL;DR: An enantioselective desymmetrization of prochiral 1,3-dinitropropanes has been developed which proceeds via enantiogroup differentiating organocatalytic allylic alkylation, and products with two vicinal stereocenters were obtained generally with good to excellent diastereoselectivity.
TL;DR: Chiral Lewis bases facilitated the synthesis of highly functionalized spirooxindoles containing α-exo-methylene-γ-butyrolactones in high yields and excellent enantioselectivities at ambient temperature.