Metal-catalyzed Cross-coupling Reactions Research Articles

The First Phosphine Oxide Ligand Precursors for Transition Metal Catalyzed Cross-Coupling Reactions: C−C, C−N, and C−S Bond Formation on Unactivated Aryl Chlorides

Schnell und regioselektiv verläuft die nucleophile Substitution an nicht aktivierten Arylchloriden mit Phosphinigsäure(RR′POH)-Metall-Komplexen (siehe Bild), für die luftstabile Phosphanoxide (RR′P(O)H) sehr geeignete Liganden-Vorstufen sind. Diese Methode kann in leistungsfähigen Katalysecyclen genutzt werden, bei denen C-C-, C-N- und C-S-Bindungen gebildet werden.

Atom-efficient metal-catalyzed cross-coupling reaction of indium organometallics with organic electrophiles.

The novel metal-catalyzed cross-coupling reaction of indium organometallics with organic electrophiles is described. Triorganoindium compounds (R(3)In) containing alkyl, vinyl, aryl, and alkynyl groups are efficiently prepared from the corresponding lithium or magnesium organometallics by reaction with indium trichloride. The cross-coupling reaction of R(3)In with aryl halides and pseudohalides (iodide 2, bromide 5, and triflate 4), vinyl triflates, benzyl bromides, and acid chlorides proceeds under palladium catalysis in excellent yields and with high chemoselectivity. Indium organometallics also react with aryl chlorides as under nickel catalysis. In the cross-coupling reaction the triorganoindium compounds transfer, in a clear example of atom economy, all three of the organic groups attached to the metal, as shown by the necessity of using only 34 mol % of indium. The feasibility of using R(3)In in reactions with different electrophiles, along with the high yields and chemoselectivities obtained, reveals indium organometallics to be useful alternatives to other organometallics in cross-coupling reactions.

Organotransition metal modified sugars: Part 22. Direct metalation of glycals: short and efficient routes to diversely protected stannylated glycals

A complete set of d-hexose-derived silyl and isopropylidene/silyl-protected glycals bearing complementary configurations at C-3 and C-4 has been synthesized in short and efficient 1–3 step sequences from standard precursors. The glycals have been applied to metalation reactions to give storable vinyl lithium equivalents by subsequent transmetalation to vinyl stannanes which represent valuable intermediates for transition metal-catalyzed cross-coupling reactions. A 1H-NMR-assisted conformational analysis has been carried out with the protected glycals and the stannylated congeners. The isopropylidene/silyl-protected glycals adopt the 4H 5-conformation caused by the bicyclic system, whereas the conformations of the fully silyl-protected monocyclic glycals are mainly controlled by the vinylogous anomeric effect. The discussed galactal- and allal-derivatives show dynamic behaviour on the NMR-time-scale. At low temperatures the two possible conformers ( 4H 5 and 5H 4) have been observed demonstrating competition of steric congestion and stereoelectronic interaction via the vinylogous anomeric effect (VAE).

Sequential substitution of 1,2-dichloro-ethene: a convenient stereoselective route to (9Z,11E)-, (10E,12Z)- and (10Z,12Z)-[1- 14C] conjugated linoleic acid isomers

Conjugated linoleic acid (CLA) isomers are present in human foods derived from milk or ruminant meat. To study their metabolism, (9Z,11E)-, (10E,12Z)- and (10Z,12Z)-[1- 14C]-octadecadienoic acids with high radiochemical and isomeric purities (>98%) were prepared by stereoselective multi-step syntheses involving sequential substitution of 1,2-dichloro-ethene. In the case of the (9Z,11E) isomer, a first metal-catalyzed cross-coupling reaction between (E)-1,2-dichloro-ethene and 2-non-8-ynyloxy-tetrahydro-pyran, obtained from 7-bromo-heptan-1-ol, gave a conjugated chloroenyne. A second coupling reaction with hexylmagnesium bromide provided a heptadecenynyl derivative. Stereoselective reduction of the triple bond and bromination afforded (7E,9Z)-17-bromo-heptadeca-7,9-diene. Formation of the Grignard reagent and carbonation with 14CO 2 gave (9Z,11E)-[1- 14C]-octadeca-9,11-dienoic acid (overall yield from 7-bromo-heptan-1-ol, 14.4%). (10E,12Z)- and (10Z,12Z)-[1- 14C]-octadeca-10,12-dienoic acids were synthesized by the same methodology using 1-heptyne, 8-bromo-octan-1-ol and, respectively, (E)-1,2-dichloro-ethene and its (Z) isomer (overall yield from 8-bromo-octan-1-ol, 13.1% (10E,12Z); 17.2% (10Z,12Z)). Impurities (<2% if present) were identified as being (E,E) CLA isomers and were removed by RP-HPLC. Metabolism studies in animal are in progress.

The preparation of amino-substituted biaryl libraries: the application of solid-supported reagents to streamline solution-phase synthesis.

A small library of isomeric benzylamino biaryls was generated in a semi-automated fashion using a solution-phase strategy employing a solid-supported, readily filterable base to facilitate electrophilic substitution followed in sequence by a metal-catalyzed cross-coupling reaction.

Towards Efficient and Wide-Scope Metal-Catalyzed Alkyl-Alkyl Cross-Coupling Reactions.

The simplest organic fragment, C(sp(3))-C(sp(3)), is unfortunately the most difficult to prepare by metal-catalyzed cross-coupling reactions (shown schematically) in the presence of functional groups. Recent advances show, however, that alkane moieties can be built within functionalized molecules by a careful choice of catalysts and conditions.

遷移金属触媒を用いる（アルコキソ）ジボロンの付加・カップリング反応を利用する有機ホウ素化合物の合成

Transition metal-catalyzed additions and cross-coupling reactions of the metal-metal compounds have attracted considerable attention as direct routes to prepare various organometallic compounds. Although the corresponding reactions of boron compounds had not yet been well developed, we recently reported the first platinum (0) -catalyzed addition reaction of bis (pinacolato) diboron (1 d) to either terminal or internal alkynes to give cis-bis (boryl) alkenes. The addition of 1 d to 1, 3-dienes and alkenes with platinum (0) complexes afforded a new access to the cis-1, 4-bis (boryl) butene and bis- (boryl) alkane derivatives. The palladium (0) -catalyzed cross-coupling reactions of 1 d with aryl halides or triflates, and allyl chlorides or acetates gave the corresponding aryl- and allylboronates in high yields, which provides the first one-step procedure for organoboronic esters from organic electrophiles. Since (alkoxo) diborons are thermally stable and easily handled in air, the reagent can be useful as boron nucleophiles for cross-coupling reactions with organic halides. The mechanisms and the synthetic applications of those reactions are discussed.

A Facile Synthetic Approach to Labeled 4-Acetoxy-2-(4-methylphenyl)benzothiazole.

To study the pharmacokinetics and metabolism of 4-acetoxy-2-(4-methylphenyl)benzothiazole (KB-2683), which has potential immunomodulating activity, a practical preparation of labeled KB-2683 was needed. This paper describes an efficient method for the synthesis of 14C-labeled KB-2683 by means of procedures which include a metal-catalyzed cross-coupling reaction.

Aryl Mesylates in Metal-Catalyzed Homocoupling and Cross-Coupling Reactions. 3. A Simple and General Method for the Synthesis of 2,2'-Diaroyl-4,4'-dihydroxybiphenyls

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTAryl Mesylates in Metal-Catalyzed Homocoupling and Cross-Coupling Reactions. 3. A Simple and General Method for the Synthesis of 2,2'-Diaroyl-4,4'-dihydroxybiphenylsVirgil Percec, Jin-Young Bae, Mingyang Zhao, and Dale H. HillCite this: J. Org. Chem. 1995, 60, 4, 1066–1069Publication Date (Print):February 1, 1995Publication History Published online1 May 2002Published inissue 1 February 1995https://doi.org/10.1021/jo00109a045RIGHTS & PERMISSIONSArticle Views791Altmetric-Citations49LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (470 KB) Get e-AlertsSupporting Info (3)»Supporting Information Supporting Information Get e-Alerts

Silyl-Substituted Conjugated Dienes: Versatile Building Blocks in Organic Synthesis

Different methods for the preparation of various silyl-substituted conjugated dienes and enynes are reviewed. Dienes having a silyl group at the terminal carbon atom are prepared by Peterson-type reactions, Wittig reactions, transition metal catalyzed cross coupling reactions, and thermal decomposition of sulfolenes in addition to other procedures. Internal silyl-substituted dienes are also prepared by similar methods (e.g. transition metal catalyzed cross coupling and thermal decomposition of sulfolenes). The synthetic applications of these dienes such as Diels-Alder reactions, coupling with electrophiles and other useful reactions are discussed

Double metal-catalyzed cross-coupling reactions of alkenyl Sulfoximines with diorganozinc reagents: Stereoselective synthesis of a key optically active 3-Oxa-Carbacyclin intermediate

A stereoselective synthesis of the diastereo- and enantiomerically pure 3-oxa-carbacyclin intermediate 2b from ketone 3 has been accomplished based on the Tamao-Kumada methodology. Nickel- and magnesium-catalyzed cross-coupling reaction of the alkenyl sulfoximine 5 with the pure diorganozinc reagent 6a led to the bicyclic allylic silane 7a and its Z isomer in a ratio of 99;1. Both were oxidized to the allylic alcohol 8 and its Z isomer, respectively. Separation of the latter and etherification of 8 gave the pure ester 2b.

Double metal-catalyzed cross-coupling reactions of alkenyl sulfoximines with diorganozinc reagents: Synthesis of optically active axial chiral allylic silanes

Nickel- and magnesium-catalyzed cross-coupling reaction of the alkenyl sulfoximine 5 with the pure diorganozinc reagents 6a and 6b gave the optically active allylic silanes 7a and 7b, respectively, Single metal catalysis was sufficient for the substitution of the bromide rac- 9 whereas the sulfone rac- 10 did neither under the conditions of single nor under that of double metal catalysis react with 6a.

N-Protected Pyrrole Derivatives Substituted for Metal-Catalyzed Cross-Coupling Reactions

The convenient synthesis of some 1-tert-butoxycarbonylpyrrole derivatives mono- and disubstituted at C-2 or at C-2 and C-5, respectively, by bromo and either boronic acid or trimethylstannyl functions is reported

Methods for the Synthesis of Allylsilanes. Part 1

This review examines the methods of preparation of allylsilanes which hold tremendous potential as reagents and intermediates in organic synthesis. The literature is covered mainly from early 1977 through late 1989. This review appears in two parts in consecutive issues. Part 1 contains Sections 1-7, and Part 2 contains Sections 8-19. Part 1 1. Introduction 2. Wittig Reaction 3. Transition Metal Catalyzed Cross-Coupling Reactions 4. From Disilanes 5. Hydrosilylation Reactions 6. Reductive Elimination of ß-Hydroxy Sulfones and ß- Hydroxy Selenides 7. Via Reagents Containing Silicon-Metal Bonds 7.1. Si-Cu 7.2. Si-Li 7.3. Si-Al 7.4. Si-Mn Part 2 8. Via Organocopper Reagents 9. Via Organoalanes 10. Via Organoboranes 11. Via Organocerium Reagents 12. By Isomerization of Silylated Olefins 13. From Allyl- and Propargylsilanes 13.1. From Allylsilanes 13.2. From Propargylsilanes 14. Diels-Alder and Ene Reactions 15. Electrochemical Synthesis 16. Photochemical Synthesis 17. Via Allylorganometallics 18. Miscellaneous Reactions 19. Conclusions

2770. PCT, a brother for PCB: Sosa-Lucero, J. C., de la Iglesia, F. A. & Thomas, G. H. (1973). Distribution of a polychlorinated Terphenyl (PCT) (Aroclor® 5460) in rat tissues and effect on hepatic microsomal mixed function oxidases. Bull. env. contam. & Toxicol. (U.S.)10, 248

Unsymmetrical terphenyl derivatives were prepared by sequential transition metal-catalyzed cross-coupling reactions of neopentyl bromobenzenesulfonates with arylboronic acids and arylmagnesium bromides in good yields. Biphenylsulfonates undergo nickel-catalyzed coupling reactions more rapidly than the corresponding benzenesulfonates. The stepwise palladium- and nickel-catalyzed reaction of the bromobenzenesulfonates appears to be a promising and conceptually straightforward route for preparing unsymmetrical terphenyls.