Showing papers on "Heck reaction published in 1993"
TL;DR: The increasing use of vinyl and aryl trifluoromethanesulfonates (triflates) is due to their facile preparation from carbonyl compounds and phenols.
Abstract: The increasing use of vinyl and aryl trifluoromethanesulfonates (triflates) is due to their facile preparation from carbonyl compounds and phenols. They undergo cross-coupling reactions with organo-metallics as the corresponding organic halides or addition reactions to alkenes and alkynes. Especially in the Heck reaction triflates proved to be superior to halides with respect to regio- and diastereoselectivity. Palladium-catalyzed carbon monoxide insertion of triflates leading to the corresponding esters or amides has found widespread application in natural product synthesis. Various deoxygenation procedures for ketones or phenols are based on the ease of removal of the trifluoromethanesulfoxy group
284 citations
TL;DR: The Heck coupling reaction between organic halides and vinylbenzene compounds was utilized to synthesize soluble and fusible conjugated polymers as discussed by the authors, and the Heck reaction offers an easier way to prepare processible poly(phenylenevinylenes).
Abstract: The Heck coupling reaction between organic halides and vinylbenzene compounds was utilized to synthesize soluble and fusible conjugated polymers. Compared to other approaches, the Heck reaction offers an easier way to prepare processible poly(phenylenevinylenes). The fusibility of the alkoxy subatituted poly(phenylenevinylene) enables us to observe the nematic liquid crystalline phase above the melting temperature
221 citations
TL;DR: In this article, the steering factors for the coordination of unsaturated systems onto palladium(0) and palladium (II) complexes were investigated for the Heck reaction with 1,10-phenanthroline derivatives as palladium ligands.
Abstract: Mechanistic studies concerning the use of 1,10-phenanthroline derivatives as palladium ligands in the Heck reaction are described. The work is focused on the steering factors for the coordination of unsaturated systems onto palladium(0) and palladium(II) complexes
126 citations
TL;DR: In this paper, an aqueous one-pot procedure starting with anilines is described for the Heck reaction of arenediazonium salts with 1.5 mol% Pd(OAC)2 in ethanol.
Abstract: Heck reaction of arenediazonium salts has been conveniently carried out with 1–2 mol% Pd(OAC)2 in ethanol. An aqueous one-pot procedure starting with anilines is described.
68 citations
TL;DR: The first total synthesis of (±)-scopadulcic acid A has been accomplished using an intramolecular bis-Heck cyclization to form the B-D rings of this tetracyclic diterpene with complete stereocontrol as discussed by the authors.
Abstract: The first total synthesis of (±)-scopadulcic acid A has been accomplished using an intramolecular bis-Heck cyclization to form the B-D rings of this tetracyclic diterpene with complete stereocontrol
65 citations
TL;DR: In this paper, a catalytic asymmetric synthesis of the key intermediates 4 and 15 for the capnellenols has been achieved through an asymmetric Heck reaction followed by the acetate anion capture process.
59 citations
TL;DR: Enone 5a, a functionalized decalin derivative, has been synthesized in up to 86% ee by an asymmetric Heck reaction starting with the allylic alcohol 3 as discussed by the authors.
58 citations
TL;DR: In this article, a facile method for the synthesis of the pharmacologically interesting 3-benzazepine skeleton is described, where the easily available iodinated benzene derivative 3 is alkylated with allyl halides to afford compounds 5a-c. Pd-catalyzed Heck-type cyclization is used to obtain 75-92% yield, with 7 and 8 being mixtures of isomers.
Abstract: A new facile method for the synthesis of the pharmacologically interesting 3-benzazepine skeleton is described. The easily available iodinated benzene derivative 3 is alkylated with allyl halides 4a-c to afford compounds 5a-c. Pd-catalyzed Heck-type cyclization leads to 3-benzazepines 6, 7, and 8 in 75-92% yield, with 7 and 8 being mixtures of isomers. Hydrogenation gives uniform 1-alkyl substituted compounds 9a-c, of which 9c is transformed into the derivatives 10, 11, and 12
56 citations
05 May 1993
TL;DR: In this article, shape-selective catalysis with zeolites and molecular sieves reactions of meta-diisopropylbenzene on acid molecular Sieves was studied.
Abstract: Selectivity in catalysis - an overview stereoselectivity - the ultimate challenge in catalysis asymmetric catalytic hydrogenation of 2-arylacrylic acids as a low-cost route to pharmaceutical products chiral rhodium (II) carboxamides - remarkably effective catalysts for enantioselective metal carbene transformations discrete chiral rhodium phosphine complexes as catalysts for asymmetric hydrosilation of ketones catalytic asymmetric heck reaction clusters, alloys, and poisoning platinum, tin, alumina catalysts - comparison of alkane dehydrocyclization activity and characterization data alkyne coordination, dimerization, and scission on a tungsten - triiridiuim cluster core - reaction modeling studies related to cluster-derived butane hydrogenolysis catalysts platinum - tin and gold - tin bimetallic particles prepared from solvated metal atoms - structure and catalysis mechanism and selectivity in catalytic olefin polymerization effect of a model hydrogenation on a catalytic palladium membrane vanadium migration between model components of fluid cracking catalysts - SEM-EDX studies shape-selective catalysis with zeolites and molecular sieves reactions of meta-diisopropylbenzene on acid molecular sieves methyl tert butyl ether and ethyl tert butyl ether - synthesis over triflic acid modified Y-zeolite design of layered phosphate hosts containing multiply bonded bimetallic guest species nuclear magnetic resonance imaging of anisotropic solid-state chemical reactions homogeneous adsorption of benzene on naX and naY zeolites reaction pathway analysis - global molecular and mechanistic perspectives preparation, characterization, and catalysis of a modified ZSM-5 zeolite effect of catalyst preparation on the aromatization of n-hexane over Pt clusters supported on hydrotalcite reactions of ethylene over ruY zeolite activation of C-H, C-C, and C-O bonds of oxygenates on rh(III) continuous catalytic conversion of acetylene to higher hydrocarbons over a metal modified shape selective zeolite catalyst characterization of ruCl, impregnated NaY zeolite non-flory product distributions in fischer-tropsch synthesis catalyzed by ruthenium, cobalt, and iron.
56 citations
TL;DR: The presence of a carbamate moiety can dramatically alter the outcome of a Heck cyclization, so that the normal exo-cyclization is not followed by β-elimination, but by cyclopropane formation, rearrangement, and elimination.
Abstract: The presence of a carbamate moiety can dramatically alter the outcome of a Heck cyclization, so that the normal exo-cyclization is not followed by β-elimination, but by cyclopropane formation, rearrangement, and elimination
45 citations
TL;DR: In this article, N-(2-bromoaryl) enaminones were prepared by several different methods, with palladium (II) acetate, triarylphosphine and triethylamine in boiling acetonitrile.
TL;DR: Bicycle enone 23a, a functionalized decalin derivative, has been synthesized in up to 86% ee by an asymmetric Heck reaction starting with bisallylic alcohol as discussed by the authors.
Abstract: Bicyclic enone 23a, a functionalized decalin derivative, has been synthesized in up to 86% ee by an asymmetric Heck reaction starting with bisallylic alcohol 24. Enone 23a has been converted to 19, a key intermediate in the synthesis of vernolepin (14). Furthermore, bicyclic dienone 43 has been synthesized in up to 83% ee from the prochiral dienone 39
TL;DR: In this paper, intramolecular Pd(0)-catalyzed cyclization of o-iodophenyl propargyl sulfide in the presence of a hydride donor gives 3-methylene-2,3-dihydrobenzo[b]thiophene, which reacts with several enophiles in ene type reactions.
TL;DR: 3-Methyleneindoline derivatives were synthesized by intramolecular Heck reaction of N-allyl-2-iodoaniline derivatives in the presence of Ag2Co3 by successfully applied to the synthesis of the CC-1065/duocarmycin pharmacophore.
Abstract: 3-Methyleneindoline derivatives were synthesized by intramolecular Heck reaction of N-allyl-2-iodoaniline derivatives in the presence of Ag2Co3. This method was successfully applied to the synthesis of the CC-1065/duocarmycin pharmacophore.
TL;DR: Starting from a judiciously substituted N-aminoindole, the Heck reaction led to a new class of heterocyclic compounds pyrido[2′,3′-d′]pyridazino[2,3a]indole as discussed by the authors.
TL;DR: The anti-microbial natural product Plicatin B has been synthesized in 53% overall yield using a Heck reaction as the key step as discussed by the authors, and the optimum conditions for this reaction have been determined.
TL;DR: In the presence of palladium C8lalysts, one of the two carbons attached to halogen in 2,2'-diiodobipbenyl couples with unsaturated organometallics, after which the other adds to the newly incorporated double bond as mentioned in this paper.
TL;DR: In this article, a Pd-catalyzed coupling with functionalized aryl and vinyl halides was proposed to provide enantiomerically pure styryl, dienyl phosphine oxides including corresponding symmetrical and nonsymmetrical bisphosphine derivatives.
Abstract: (S)-Methylphenylvinylphosphine oxide ( 1 ) undergoes facile Pd-catalyzed coupling with functionalized aryl and vinyl halides to provide new enantiomerically pure styryl and dienyl phosphine oxides including also the corresponding symmetrical and nonsymmetrical bisphosphine derivatives.
TL;DR: In this paper, the Heck coupling between 5-bromopyrimidine and tert-butyl acrylate undergoes nearly quantitative Michael addition in t-butanol saturated with ammonia to the hitherto unknown β-amino-5-pyrimidinepropanoic ester 4.
TL;DR: In this paper, 1,3-Dioxep-5-ene derivatives were arylated by using Heck reaction, and the derivatives were easily converted into 4-arylbutyrolactones, intermediates for the synthesis of natural products and biological active compounds.
Abstract: 1,3-Dioxep-5-ene was arylated by using Heck reaction, and the arylated 1,3-dioxep-4-ene derivatives were easily converted into 4-arylbutyrolactones, intermediates for the synthesis of natural products and biological active compounds
TL;DR: In this paper, the displacement of the specific 3 H-ouabain binding to Na +, K + -ATPase was evaluated in the synthesis of 1-(4-substituted)benzyl-6-hydroxy isoquinolines.
TL;DR: In this paper, a trans, trans-2,5thienylenevinylene-1,4-phenylene-vinylene moiety was prepared by palladium-catalyzed polycondensation.
Abstract: Polymers containing a trans, trans-2,5-thienylenevinylene-1,4-phenylenevinylene moiety were prepared by palladium-catalyzed polycondensation. Couples of 2,5-divinylthiophene derivatives 1 with p-dihalobenzenes 2 successfully produced the expected polymers 5, whereas couples of 2,5-dihalothiophene derivatives 3 with p-divinylbenzene 4 gave only oligomers due to the homo-coupling reaction of 3. Synthesis of a thermotropic liquid crystalline polymer having trans, trans-2,5-distyrylthiophene skeletons as mesogen was also investigated by use of the polyconcensation between 1 and bis(p-iodophenyl) compounds 6 that concurrently have flexible segments.
TL;DR: Palladium complexes catalyze versatile and useful reactions, such as ring-opening polymerization, polycondensation, polyaddition, and addition polymerization as mentioned in this paper, which are reviewed in this article.
Abstract: It has been well documented that palladium complexes catalyze versatile and useful reactions. Contemplation of these reactions from the standpoint of polymer synthesis has brought new polymerizations, which are reviewed in this article including topics of ring-opening polymerization, polycondensation, polyaddition, and addition polymerization. 1) A new type of ring-opening polymerization, whose key intermediates were π-allyl palladium complexes, was developed. Especially, for the polymerization of cyclic carbamates was designed and achieved an unusual mode that propagating ends multiply at every step of propagation. The produced polyamines had hyperbranched dendritic structures incorporating the initiator as the core. 2) Aromatic polymers such as poly (phenylene vinylene) s, polyphenylenes, and polyamides were prepared by the Heck reaction and Pd-catalyzed cross-coupling reactions. 3) Electrophilic palladium complexes initiated vinyl polymerizations of styrene, methyl propiolate, norbornene, etc. as well as alternating copolymerizations of some alkenes with carbon monoxide. Bromo (methyl) palladium-phosphine complexes initiated living aromatization polymerizations of 1, 2-diisocyanoarenes. 4) A cyclic compound having a Si-Si bond, 1, 2-disilacyclopentane, was polymerized with the aid of a Pd (0) complex.
TL;DR: In this paper, the Heck reaction was used to synthesize Arylazostilbenes and -tolanes by coupling p-bromo azo dyes with styrenes and arylacetylenes.
Abstract: Synthesis of Arylazostilbenes and -tolanes by the Heck Reaction
The palladium-catalysed coupling of p-bromo azo dyes 4 with styrenes 6 and arylacetylenes 9 provides arylazostilbenes 7 and -tolanes 10, respectively, in fair-to-good yields. Likewise, coupling of azoxy compound 5 with styrenes 6 forms the arylazoxystilbenes 8 in high yields. The influence of substituentes on light absorption of the new dyes as well as on the 13C-NMR shifts of the azotolanes 10 are discussed.
Patent•
30 Apr 1993TL;DR: In this paper, an intramolecular Heck stereospecific synthesis of 2-chloro-cis-[5a(S)-9a-9a (S)-(5a,6,7,8,9, 9, 9a-hexahydro)]dibenzofuran-4-carboxylic acid was presented.
Abstract: The present invention is directed to the synthesis of 2-chloro-cis-[5a(S)-9a(S)-(5a,6,7,8,9,9a-hexahydro)]dibenzofuran-4-carboxylic acid by an intramolecular Heck stereospecific synthesis substantially free of undesirable 8-chloro-2,6-methano-2H-3,4,5,6-tetrahydro-1-benzoxocin-10-carboxylic.
TL;DR: The anti-microbial natural product Plicatin B has been synthesized in 53% overall yield using a Heck reaction as the key step as discussed by the authors, and the optimum conditions for this reaction have been determined.
Abstract: The anti-microbial natural product Plicatin B has been synthesized in 53% overall yield using a Heck reaction as the key step. The optimum conditions for this reaction have been determined. Halophenols proved much less reactive than their corresponding acetates.
TL;DR: In this article, an asymmetric Heck reaction was applied to catalytic asymmetric syntheses of cis-decalin derivatives, cis-hydrindan derivatives and polycyclopentanoids with enantiomeric excesses ranging from 80% to 92%.
Abstract: In 1989 we succeeded in demonstrating the first example of an asymmetric Heck reaction. Since then, an asymmetric Heck reaction has been successfully applied to catalytic asymmetric syntheses of cis-decalin derivatives, cis-hydrindan derivatives and polycyclopentanoids with enantiomeric excesses ranging from 80% to 92%. Formation of 16-electron Pd+ intermediates has been found to be essential to obtain products with high ees. Furthermore, in 1991 we succeeded in demonstrating the first example of a catalytic asymmetric nitroaldol reaction utilizing an optically active lanthanum complex, which gave a nitroaldol in up to 95% ee.
TL;DR: In this article, Nallyl-2-iodoaniline derivatives were synthesized by intramolecular Heck reaction of N-allyl 2.3-Methyleneindoline derivatives in the presence of Ag2Co3.
Abstract: 3-Methyleneindoline derivatives were synthesized by intramolecular Heck reaction of N-allyl-2-iodoaniline derivatives in the presence of Ag2Co3. This method was successfully applied to the synthesis of the CC-1065/duocarmycin pharmacophore.