scholarly journals A domino reaction for generating β-aryl aldehydes from alkynes by substrate recognition catalysis

2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Weiwei Fang ◽  
Felix Bauer ◽  
Yaxi Dong ◽  
Bernhard Breit
Keyword(s):  
Substrate Recognition ◽  
Domino Reaction ◽  
Chemical Transformations ◽  
Reaction Sequence ◽  
Reaction Conditions ◽  
Consecutive Reaction ◽  
Aryl Aldehydes ◽  
Rh Catalyst ◽  
Catalyst Systems ◽  
Step Control

Abstract The development of universal catalyst systems that enable efficient, selective, and straightforward chemical transformations is of immense scientific importance. Here we develop a domino process comprising three consecutive reaction steps based on the strategy of supramolecular substrate recognition. This approach provides valuable β-aryl aldehydes from readily accessible α-alkynoic acids and arenes under mild reaction conditions, employing a supramolecular Rh catalyst containing an acylguanidine-bearing phosphine ligand. Furthermore, the synthesis of a key intermediate of Avitriptan using this protocol is accomplished. The first step of the reaction sequence is proved to be the regioselective hydroformylation of α-alkynoic acids. Remarkably, molecular recognition of the ligand and the substrate via hydrogen bonding plays a key role in this step. Control experiments indicate that the reaction further proceeds via 1,4-addition of an arene nucleophile to the unsaturated aldehyde intermediate and subsequent decarboxylation.

Synthesis of pyrazolo[1,5-c]quinazoline derivatives through the copper-catalyzed domino reaction of o-alkenyl aromatic isocyanides with diazo compounds

2020 ◽  
Vol 56 (55) ◽  
pp. 7665-7668 ◽  
Author(s):  
Lu Liu ◽  
Lei Li ◽  
Shukuan Mao ◽  
Xin Wang ◽  
Ming-Dong Zhou ◽  
...  
Keyword(s):  
Diazo Compounds ◽  
Domino Reaction ◽  
Reaction Conditions ◽  
One Pot ◽  
One Pot Synthesis ◽  
Quinazoline Derivatives

Various o-alkenyl aromatic isocyanides were prepared from readily available reactants for their double annulation with diazo compounds for a one-pot synthesis of pyrazolo[1,5-c]quinazolines under mild reaction conditions.

A Synthesis of 2-Amino-2,6-dideoxy-D-(and L-)galaetose (Fucosamine) and 2-Amino-2,6-dideoxy-D-(and L-)talose (Pneumosamine)

1973 ◽  
Vol 51 (6) ◽  
pp. 974-977 ◽  
Author(s):  
Malcolm B. Perry ◽  
Virginia Daoust
Keyword(s):  
Similar Reaction ◽  
Reaction Sequence ◽  
Reaction Conditions ◽  
Nef Reaction ◽  
Methanolic Ammonia

5-Deoxy-D-lyxose underwent base-catalyzed addition with nitromethane to give a mixture of 1,6-dideoxy-1-nitro-D-galactitol and 1,6-dideoxy-1-nitro-D-talitol (ca. 2:1). Acetylation of the crystalline 1,6-dideoxy-1-nitro-D-galactitol gave 2,3,4,5-tetra-O-acetyl-1,6-dideoxy-1-nitro-D-galactitol which on treatment with methanolic ammonia afforded 2-acetamido-1,2,6-trideoxy-1-nitro-D-talitol and 2-acetamido-1,2,6-trideoxy-1-nitro-D-galactitol (ca. 3:1) which under the modified Nef reaction conditions gave 2-acetamido-2,6-dideoxy-D-talose and 2-acetamido-2,6-dideoxy-D-galactose respectively. The glycoses were converted to 2-amino-2,6-dideoxy-D-talose hydrochloride and 2-amino-2,6-dideoxy-D-galactose hydrochloride on hydrolysis with hydrochloric acid.A similar reaction sequence applied to 5-deoxy-L-lyxose afforded the L-enantiomorphic intermediates, and gave 2-amino-2,6-dideoxy-L-talose hydrochloride and 2-amino-2,6-dideoxy-L-galactose hydrochloride as final products.

scholarly journals Appel-reagent-mediated transformation of glycosyl hemiacetal derivatives into thioglycosides and glycosyl thiols

2013 ◽  
Vol 9 ◽  
pp. 974-982 ◽  
Author(s):  
Tamashree Ghosh ◽  
Abhishek Santra ◽  
Anup Kumar Misra
Keyword(s):  
Reaction Sequence ◽  
Reaction Conditions ◽  
One Pot ◽  
Carbon Tetrabromide

A series of glycosyl hemiacetal derivatives have been transformed into thioglycosides and glycosyl thiols in a one-pot two-step reaction sequence mediated by Appel reagent (carbon tetrabromide and triphenylphosphine). 1,2-trans-Thioglycosides and β-glycosyl thiol derivatives were stereoselectively formed by the reaction of the in situ generated glycosyl bromides with thiols and sodium carbonotrithioate. The reaction conditions are reasonably simple and yields were very good.

scholarly journals Efficient synthesis of pyrazolopyridines containing a chromane backbone through domino reaction

2019 ◽  
Vol 15 ◽  
pp. 874-880
Author(s):  
Razieh Navari ◽  
Saeed Balalaie ◽  
Saber Mehrparvar ◽  
Fatemeh Darvish ◽  
Frank Rominger ◽  
...  
Keyword(s):  
Room Temperature ◽  
High Selectivity ◽  
Domino Reaction ◽  
Primary Amines ◽  
Efficient Synthesis ◽  
Atom Economy ◽  
Reaction Conditions ◽  
Efficient Approach ◽  
Three Component Reaction ◽  
High Yields

An efficient approach for the synthesis of pyrazolopyridines containing the aminochromane motif through a base-catalyzed cyclization reaction is reported. The synthesis was carried out through a three-component reaction of (arylhydrazono)methyl-4H-chromen-4-one, malononitrile, primary amines in the presence of Et3N at room temperature. However, carrying out the reaction under the same conditions without base led to a fused chromanyl-cyanopyridine. High selectivity, high atom economy, and good to high yields in addition to mild reaction conditions are the advantages of this approach.

scholarly journals Deoxydehydration of vicinal diols by homogeneous catalysts: a mechanistic overview

2019 ◽  
Vol 6 (11) ◽  
pp. 191165 ◽  
Author(s):  
Kayla A. DeNike ◽  
Stefan M. Kilyanek
Keyword(s):  
Reaction Mechanism ◽  
Product Distribution ◽  
Catalytic Cycle ◽  
Reaction Conditions ◽  
Homogeneous Catalysts ◽  
Commodity Chemicals ◽  
Reduction Methods ◽  
Vicinal Diols ◽  
Catalyst Systems

Deoxydehydration (DODH) is an important reaction for the upconversion of biomass-derived polyols to commodity chemicals such as alkenes and dienes. DODH can be performed by a variety of early metal-oxo catalysts incorporating Re, Mo and V. The varying reduction methods used in the DODH catalytic cycle impact the product distribution, reaction mechanism and the overall yield of the reaction. This review surveys the reduction methods commonly used in homogeneous DODH catalyst systems and their impacts on yield and reaction conditions.

scholarly journals Microwave Assisted One Pot Synthesis of 3,4-Dihydropyrano[c]chromene Derivatives using [Emim]OH Ionic Liquid as Novel Catalyst

2019 ◽  
Vol 31 (4) ◽  
pp. 829-833
Author(s):  
D.S. Bhagat ◽  
S.G. Pande ◽  
M.V. Katariya ◽  
R.P. Pawar ◽  
P.S. Kendrekar
Keyword(s):  
Ionic Liquid ◽  
Reaction Time ◽  
High Yield ◽  
Reaction Conditions ◽  
One Pot ◽  
Short Reaction Time ◽  
Aryl Aldehydes ◽  
Microwave Assisted ◽  
Novel Catalyst ◽  
Work Up

One-pot efficient protocol to the synthesis of 2-amino-5-oxo-4,5-dihydropyrano(3,2-c)chromene-3-carbonitrile derivatives via condensation of various aryl aldehydes, dicyanomethane and 4-hydroxycoumarin in presence of Emim hydroxide as an excellent homogeneous liquid catalyst. The key advantages of this methodology are mild reaction conditions, novel catalyst, short reaction time, eco-friendly, easy work-up procedure and high yield of isolation of derivatives.

scholarly journals Domino Reaction Sequence for the Synthesis of [2.2.2]Diazabicycloalkenes and Base-Promoted Cycloreversion to 2-Pyridone Alkaloids

2018 ◽  
Vol 20 (17) ◽  
pp. 5203-5207 ◽  
Author(s):  
Nicholas H. Angello ◽  
Robert E. Wiley ◽  
Tristan G. Elmore ◽  
Ryan S. Perry ◽  
Jonathan R. Scheerer
Keyword(s):  
Domino Reaction ◽  
Reaction Sequence

scholarly journals The Study of the Reaction of Pectin-Ag(0) Nanocomposites Formation

2012 ◽  
Vol 2012 ◽  
pp. 1-9 ◽  
Author(s):  
Nadezhda Viktorovna Ivanova ◽  
Natalya Nikolaevna Trofimova ◽  
Lydmila Alexandrovna Es'kova ◽  
Vasilyi Anatolievich Babkin
Keyword(s):  
Aqueous Solutions ◽  
Larix Sibirica ◽  
Side Chains ◽  
Chemical Transformations ◽  
Reaction Conditions ◽  
Rhamnogalacturonan I ◽  
Spectroscopic Analyses ◽  
Furanose Form ◽  
Branched Structure ◽  
C Nmr

Pectin polysaccharides (PSs) were isolated from a bark of Larix sibirica Ledeb. Structure of PS fragments determined by chemical transformations, chromatography, and spectroscopic analyses was found to be a linear galacturonane comprising 1,4-linked α-D-GalpA residues and a rhamnogalacturonan I (RG-I). The fifth part of galacturonane residues was methyl esterified at at C-2 and/or C-3 and C-6 atoms. Some of RG-I side chains were identified as arabinogalactan subunits with highly branched structure consisting of linear backbone with3,6)-β-D-Galp-(1residues, substituted at C-6 by neutral side chains. This side chains contained2,5)-α-L-Araf-(1and3,5)-α-L-Araf-(1residues and terminal arabinose in the pyranose and furanose form. It was found that “pectin-Ag(0)” nanobiocomposites were formed via the interaction between PS aqueous solutions and silver nitrate, with PS playing both reducing and stabilizing functions. It was shown that the content of Ag(0) particles in “pectin-Ag(0)” depended on the reaction conditions and can range from 0.1 to 72 %, the size of Ag(0) particles being 3–27 nm. Using 13C NMR technique, it was revealed that PS underwent destructive changes and they they were more considerable, more than the lot of Ag(I) that was inputed into the reactionary medium.

Cyclocondensation-Knoevenagel–Michael Domino reaction of phenyl hydrazine, acetoacetate derivatives and aryl aldehydes over acetic acid functionalized ionic liquid

2015 ◽  
Vol 42 (5) ◽  
pp. 4759-4772 ◽  
Author(s):  
Ahmad Reza Moosavi-Zare ◽  
Mohammad Ali Zolfigol ◽  
Ehsan Noroozizadeh ◽  
Omid Khaledian ◽  
Behzad Shirmardi Shaghasemi
Keyword(s):  
Ionic Liquid ◽  
Acetic Acid ◽  
Domino Reaction ◽  
Phenyl Hydrazine ◽  
Functionalized Ionic Liquid ◽  
Aryl Aldehydes

scholarly journals Thermal aromatic Claisen rearrangement and Strecker reaction of alkyl(allyl)-aryl ethers under green reaction conditions: Efficient and clean preparation of ortho-allyl phenols (naphthols) and alkyl(allyl)oxyarene-based γ-amino nitriles

2017 ◽  
Vol 6 (6) ◽  
pp. 208-214
Author(s):  
Kheila N. Silgado-Gómez ◽  
Vladimir V. Kouznetsov
Keyword(s):  
Claisen Rearrangement ◽  
Potassium Cyanide ◽  
Solid Catalyst ◽  
Chemical Transformations ◽  
Reaction Conditions ◽  
Alkyl Aryl ◽  
Strecker Reaction ◽  
Aryl Ethers ◽  
Short Time ◽  
Aromatic Claisen Rearrangement

Chemical transformations of 13 diverse allyl(alkyl)-aryl ethers, easily prepared using Williamson reaction of different hydroxyarenes and allyl bromide and alkyl (n-butyl, n-octyl) bromides, were studied. Thermal aromatic Claisen rearrangement of allyl-aryl ethers to obtain ortho-allyl phenols (naphthols) employing propylene carbonate as a nontoxic and biodegradable solvent was described for the first time. The use of this green solvent allowed to enhance notably product yields and reduce significantly the reaction time comparing with the use of 1,2-dichlorobenzene, toxic solvent, which is traditionally employed in this type of Claisen rearrangement. Three-component Strecker reaction of selected alkyl(allyl)-aryl ethers with formyl function on aryl fragment, piperidine and potassium cyanide in the presence of sulfuric acid supported on silica gel (SSA, SiO2-O-SO3H) under mild reaction conditions was used in the preparation of new γ-amino nitriles, analogues of alkaloid girgensohnine [2-(4-hydroxyphenyl)-2-(piperidin-1-yl)acetonitrile], a perspective biological model in the search for new insecticidal agrochemicals against Aedes aegypti. The use of SSA, an inexpensive and reusable solid catalyst, allowed to obtain new series of 2-[4-alkyl(allyl)oxyphenyl]-2-(piperidin-1-yl)acetonitriles in short time at room temperature with good yields.

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