Highly Efficient Synthesis (highly + efficient_synthesis)

Distribution by Scientific Domains
Distribution within Chemistry


Selected Abstracts


A Highly Efficient Synthesis of a Naphthalenoid Histamine-3 Antagonist

ADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 11-12 2009
Yi-Yin Ku
Abstract A highly efficient synthesis of the potent and selective histamine-3 receptor antagonist 1A was accomplished in four chemical steps and a salt formation step in 36% overall yield from 6-bromo-2-naphthalenol 9. The key features are a regioselective Suzuki coupling protocol for selective vinylation of 12 with potassium vinyltrifluoroborate in high yield (92%) with excellent regioselectivity (90:2) and a base-catalyzed hydroamination reaction of 11 in an anti-Markovnikov fashion under mild reaction conditions. An optimized copper-catalyzed cross coupling reaction is used to incorporate the pyridazinone 4. [source]


Catalytic Asymmetric Bromoamination of Chalcones: Highly Efficient Synthesis of Chiral ,-Bromo-,-Amino Ketone Derivatives,

ANGEWANDTE CHEMIE, Issue 35 2010
Yunfei Cai
Sparsam mit dem Katalysator: In der unter milden Bedingungen über eine Bromonium-Zwischenstufe verlaufenden Titelreaktion wurden mit 0.05,Mol-% eines C2 -symmetrischen N,N,-Dioxid-Scandium(III)-Komplexes hervorragende Resultate erzielt (siehe Schema). [source]


ChemInform Abstract: Cyclodehydration of Fluorinated Diols Using the Mitsunobu Reaction: Highly Efficient Synthesis of Trifluoromethylated Cyclic Ethers.

CHEMINFORM, Issue 40 2010
G. K. Surya Prakash
Abstract The title reaction of the diastereomerically pure diol (VII) affords the corresponding oxirane (VIII) with complete inversion of configuration. [source]


ChemInform Abstract: Highly Efficient Synthesis of Phenols by Copper-Catalyzed Oxidative Hydroxylation of Arylboronic Acids at Room Temperature in Water.

CHEMINFORM, Issue 36 2010
Jimin Xu
Abstract The method is compatible with various functionalities and affords the desired phenols in good to excellent yields. [source]


ChemInform Abstract: Iron-Catalyzed Selective Oxidation of N-Methyl Amines: Highly Efficient Synthesis of Methylene-Bridged Bis-1,3-dicarbonyl Compounds.

CHEMINFORM, Issue 5 2010
Haijun Li
Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source]


ChemInform Abstract: Prins Cyclization in Ionic Liquid Hydrogen Fluoride Salts: Facile and Highly Efficient Synthesis of 4-Fluorinated Tetrahydropyrans, Thiacyclohexanes, and Piperidines.

CHEMINFORM, Issue 18 2009
Yuichiro Kishi
Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source]


ChemInform Abstract: Bismuth(III)-Catalyzed Rapid and Highly Efficient Synthesis of 2-Aryl-1-arylmethyl-1H-benzimidazoles in Water.

CHEMINFORM, Issue 33 2008
J. S. Yadav
Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source]


A Highly Efficient Synthesis of 1,2,3,4-Tetrahydroquinolines by Molecular Iodine Catalyzed Domino Reaction of Anilines with Cyclic Enol Ethers.

CHEMINFORM, Issue 40 2006
Xu-Feng Lin
Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF. [source]


ChemInform Abstract: Highly Efficient Synthesis of 1H-Quinazoline-2,4-diones Using Carbon Dioxide in the Presence of Catalytic Amount of DBU.

CHEMINFORM, Issue 37 2002
Takumi Mizuno
Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source]


ChemInform Abstract: A Practical and Highly Efficient Synthesis of ,-(Trimethylsilyl)-difluoroacetates.

CHEMINFORM, Issue 13 2001
Hideki Amii
Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source]


Intramolecular Photochemical Cross-Coupling Reactions of 3-Acyl-2-haloindoles and 2-Chloropyrrole-3-carbaldehydes with Substituted Benzenes

ADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 17 2009
Shen-Ci Lu
Abstract Highly efficient syntheses of indolo[2,1- a]isoquinolines, indolo[2,1- a][2]benzazepines, pyrrolo[2,1- a]isoquinolines and pyrrolo[1,2- a]benzazepines in excellent yields have been achieved by the intramolecular photochemical cross-coupling reactions of 3-acyl-2-halo- N -(,-arylalkyl)indoles and 2-chloro- N -(,-arylalkyl)pyrrole-3-carbaldehydes in acetone. A new heterocyclic ring system , pyrrolo[1,2- d][1,4]benzoxazepine , has also been constructed for the first time in this work by the photocyclization of 2-chloro- N -(2-phenoxyethyl)pyrrole-3-carbaldehyde. [source]


Highly efficient synthesis of [11C]S12968 and [11C]S12967, for the in vivo imaging of the cardiac calcium channels using PET

JOURNAL OF LABELLED COMPOUNDS AND RADIOPHARMACEUTICALS, Issue 7 2001
Frédéric Dolle
Abstract The dihydrophyridines S12968 ((,)-S11568, absolute configuration S) and S12967 ((+)-S11568, absolute configuration R), 3-ethyl 5-methyl (,/+)-2-[(2-(2-aminoethoxy)ethoxy)methyl]-4-(2,3-dichlorophenyl)-6-methyl-1,4-dihydropyridine-3,5-dicarboxylate, have both an in vitro profile of high potency and of high selectivity for the low-voltage-dependent L-type calcium channel. In this paper, the radiosynthesis of both enantiomers, S12968 and S12967, with carbon-11, a positron-emitting isotope (half-life : 20.4 min) was investigated and oriented towards the preparation of multi milliCuries of radiotracer. Typically, 130,250 mCi (4.81,9.25 GBq) of [11C]S12968 and [11C]S12967 were obtained within 30 min of radiosynthesis (HPLC purification included) with specific radioactivities ranging from 500 to 1000 mCi/,mol (18.5,37.0 GBq/,mol) using no-carrier-added [11C]methyl triflate as the alkylating agent and the appropriate, enantiomerically pure carboxylic acid precursor at 100°C for 1 min. Based on preliminary PET experiments, only the levo enantiomer S12968 ((,)-[11C]-1) appears to be suitable for myocardial PET imaging as demonstrated in vivo in beagle dogs: with S12968, 85% of the uptake of [11C]S12968 could be inhibited in pretreatment experiments and up to 70% of [11C]S12968 could be displaced. Further investigations are currently underway in order to provide an absolute quantification of ventricular calcium channels with PET. Copyright © 2001 John Wiley & Sons, Ltd. [source]


Highly Efficient Synthesis of Enantiopure Diacetylated C2 -Symmetric Diols by Ruthenium- and Enzyme-Catalyzed Dynamic Kinetic Asymmetric Transformation (DYKAT)

CHEMISTRY - A EUROPEAN JOURNAL, Issue 23 2006
Belén Martín-Matute Dr.
Abstract Highly efficient synthesis of enantiopure diacetates of 2,4-pentanediol and 2,5-hexanediol starting from commercially available mixtures of the diols (dl/meso ,1:1) has been realized by combining a fast ruthenium-catalyzed epimerization with an enzymatic transesterification. The in situ coupling of these two processes produces the diacetates in high yield in >99,% enantiomeric excess. [source]


Highly efficient synthesis of peptides by rational utilization of novel coupling reagents

CHINESE JOURNAL OF CHEMISTRY, Issue 4 2000
Li Peng
Abstract The efficiency of different peptide coupling reagents, including carbodiimides, HOBt or HOAt-derived uronium, phosphonium and immonium salts, halouronium, halophosphonium, 2-halopyridinium and 2-halothiazolium salts, was evaluated. The synthetic strategy for coded peptides and nonribosomal peptides was discussed with an emphasis on the rational selection of peptide coupling reagents. [source]


A Highly Efficient Synthesis of a Naphthalenoid Histamine-3 Antagonist

ADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 11-12 2009
Yi-Yin Ku
Abstract A highly efficient synthesis of the potent and selective histamine-3 receptor antagonist 1A was accomplished in four chemical steps and a salt formation step in 36% overall yield from 6-bromo-2-naphthalenol 9. The key features are a regioselective Suzuki coupling protocol for selective vinylation of 12 with potassium vinyltrifluoroborate in high yield (92%) with excellent regioselectivity (90:2) and a base-catalyzed hydroamination reaction of 11 in an anti-Markovnikov fashion under mild reaction conditions. An optimized copper-catalyzed cross coupling reaction is used to incorporate the pyridazinone 4. [source]


A highly efficient synthesis of (Z)-1-aryl-2-silyl-1- stannylethenes and their conversion to (E)-2- arylethenyl-, (Z)-2-(2-pyridyl)ethenyl- and allenyl-silanes

APPLIED ORGANOMETALLIC CHEMISTRY, Issue 3 2007
Takanori Endo
Abstract A Pd(dba)2,P(OEt)3 combination allowed the silastannation of arylacetylenes, 1-hexyne or propargyl alcohols with tributyl(trimethylsilyl)stannane to take place at room temperature, producing (Z)-2-silyl-1-stannyl-1-substituted ethenes in high yields. Novel silyl(stannyl)ethenes were fully characterized by 1H-, 13C-, 29Si- and 119Sn-NMR as well as infrared and mass analyses. Treatment of a series of (Z)-1-aryl-2-silyl-1-stannylethenes and (Z)-1-(3-pyridyl)-2-silyl-1-stannylethene with hydrochloric acid or hydroiodic acid in the presence of tetraethylammonium chloride (TEACl) or tetrabutylammonium iodide (TBAI) led to the exclusive formation of (E)-trimethyl(2-arylethenyl)silanes with high stereoselectivity. A similar reaction of (Z)-1-(2-anisyl)-2-silyl-1-stannylethene also produced E -type trimethyl[2-(2-anisyl)ethenyl]silane, while (Z)-trimethyl [2-(2-pyridyl)ethenyl]silane was produced exclusively from (Z)-1-(2-pyridyl)-2-silyl-1-stannylethene. Protodestannylation of (Z)-1-[hydroxy(phenyl)methyl]-2-silyl-1-stannylethene with trifluoroacetic acid took place via the ,-elimination of hydroxystannane, providing trimethyl(3-phenylpropa-1,2-dienyl)silane quite easily. The destannylation products were also fully characterized. Copyright © 2007 John Wiley & Sons, Ltd. [source]