scholarly journals A One-pot Access to Diastereoselective Benzo[5,6]oxepino[2,3-c]pyrroles via Formal (5+2)-Annulation of Donor-/Acceptor-Type Aryl Vinyl diazosuccinimide with Ketones Under Silver Catalysis

2021 ◽  
Author(s):  
Dr. Ramakrishna G. Bhat ◽  
Debasish Laha ◽  
Kajal B. Meher ◽  
Onkar S. Bankar
Keyword(s):  
Diazo Compounds ◽  
Diastereoselective Synthesis ◽  
Methyl Ketones ◽  
Nmr Studies ◽  
One Pot ◽  
Efficient Catalyst ◽  
Silver Catalysis ◽  
Single Diastereomer ◽  
Donor Acceptor ◽  
Plausible Mechanism

A silver triflimide catalyzed one-pot protocol for the diastereoselective synthesis of dihydrobenzoxepines has been developed. Silver triflimide found to be an efficient catalyst for the formal (5+2)-cycloaddition to access dihydrobenzoxepines as a single diastereomer using vinyl diazo compounds as 5-C-synthons and ketones. An unmet challenge of utilizing the donor-/acceptor-type vinyl diazosuccinimides as 5-C-synthons under silver-catalysis is presented. This protocol found to be highly regio-, chemo- and diastereoselective, and works well with aliphatic as well as aromatic methyl ketones bearing electron deactivating as well as donating groups to afford dihydrobenzo[5,6]oxepino[2,3-c]pyrroles with a broad substrates scope. The control experiments and time dependent NMR studies revealed the plausible mechanism of this transformation. The protocol also proved to be scalable on the gram scale synthesis.

scholarly journals One-pot three-component tandem annulation of 4-hydroxycoumarine with aldehyde and aromatic amines using graphene oxide as an efficient catalyst

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Rabindranath Singha ◽  
Aminul Islam ◽  
Pranab Ghosh
Keyword(s):  
Graphene Oxide ◽  
Catalytic Activity ◽  
Aromatic Amines ◽  
Significant Loss ◽  
Solvent Free ◽  
One Pot ◽  
Efficient Catalyst ◽  
New Class ◽  
Broad Scope ◽  
Plausible Mechanism

AbstractA convenient and efficient solvent-free, facile, one-pot three-component graphene oxide catalysed approach has been described for the synthesis of chromeno-[4,3-b]quinolin-6-one derivatives from 4-hydroxycoumarin with aldehydes and aromatic amines. Graphene oxide (GO) has proved to be a new class of heterogeneous carbocatalyst which could be easily recovered and reused up to 5th run without significant loss of its catalytic activity. A broad scope of substrate applicability is offered and a plausible mechanism is also suggested for this developed protocol.

Diastereoselective Synthesis of Functionalised Trans-Tetrahydrobenzofuran-4-Ones in an Aqueous Medium by using DABCO as an Efficient Catalyst

2017 ◽  
Vol 41 (11) ◽  
pp. 657-660 ◽  
Author(s):  
Mohammad Reza Salari ◽  
Mohammad H. Mosslemin ◽  
Alireza Hassanabadi
Keyword(s):  
Aqueous Medium ◽  
High Purity ◽  
Reaction Times ◽  
Diastereoselective Synthesis ◽  
Efficient Synthesis ◽  
One Pot ◽  
Efficient Catalyst ◽  
Pyridinium Bromide ◽  
Work Up

A one-pot, efficient synthesis of 11 novel 2,3-diacylated trans-tetrahydrobenzofuran-4-one derivatives has been achieved via a three-component condensation of a N-(4-halophenacyl)-pyridinium bromide, a cyclic 1,3-diketone such as 5,5-dimethyl-1,3-cyclohexanedione (dimedone) or cyclohexane-1,3-dione and an arylglyoxal in the presence of catalytic amounts of 1,4-diaza-bicyclo[2.2.2]octane (DABCO) in water under reflux conditions. The attractive features of the method are excellent yields and high purity, short reaction times, easy work-up, and use of an inexpensive and non-toxic catalyst.

scholarly journals An air-stable bisboron complex: a practical bidentate Lewis acid catalyst

2018 ◽  
Vol 14 ◽  
pp. 618-625 ◽  
Author(s):  
Longcheng Hong ◽  
Sebastian Ahles ◽  
Andreas H Heindl ◽  
Gastelle Tiétcha ◽  
Andrey Petrov ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Acid Catalyst ◽  
Diels Alder ◽  
Organic Transformations ◽  
Nmr Studies ◽  
One Pot ◽  
Efficient Catalyst ◽  
Inverse Electron Demand ◽  
Lewis Acid Catalyst ◽  
Electron Demand

We report an air-stable bisboron complex as an efficient catalyst for the inverse electron-demand Diels–Alder (IEDDA) reaction of 1,2-diazine as well as 1,2,4,5-tetrazine. Its stability towards air and moisture was demonstrated by NMR studies enabling its application in organic transformations without glovebox. A one-pot procedure for its synthesis was developed starting from 1,2-bis(trimethylsilyl)benzene greatly enhancing its practicality. Comparative reactions were carried out to evaluate its catalytic activity in IEDDA reactions of diazine including phthalazine as well as 1,2,4,5-tetrazine.

scholarly journals SALICYLIC ACID AS AN EFFICIENT CATALYST FOR THE DIASTEREOSELECTIVE SYNTHESIS OF DISPIROHYDROQUINOLINES VIA A ONE-POT DOMINO EIGHT-COMPONENT REACTION

2018 ◽  
Vol 63 (4) ◽  
pp. 4159-4164
Author(s):  
Sajjad Salahi ◽  
Nourallah Hazeri ◽  
Malek Taher Maghsoodlou ◽  
Mojtaba Lashkari ◽  
Niloufar Akbarzadeh Torbati ◽  
...  
Keyword(s):  
Salicylic Acid ◽  
Diastereoselective Synthesis ◽  
One Pot ◽  
Efficient Catalyst

DABCO as an Efficient Catalyst for the Diastereoselective Synthesis of trans-(4-chlorophenyl)-7-aryl-6,7-dihydro-[1,3]dioxolo[4,5-f]benzofuran-6-yl) Methanone in an Aqueous Medium

2017 ◽  
Vol 41 (1) ◽  
pp. 60-63 ◽  
Author(s):  
Maryam Salari ◽  
Mohammad H. Mosslemin ◽  
Alireza Hassanabadi
Keyword(s):  
Aqueous Medium ◽  
Aromatic Aldehyde ◽  
Diastereoselective Synthesis ◽  
One Pot ◽  
Efficient Catalyst ◽  
Excellent Yield ◽  
One Pot Condensation ◽  
Short Time

A three-component one-pot condensation of 2-[2-(4-chlorophenyl)-2-oxoethyl)]isoquinolinium bromide with benzo[1,3]dioxol-5-ol and an aromatic aldehyde in the presence of catalytic amounts of 1,4-diaza-bicyclo[2.2.2]octane (DABCO) in refluxing water gives trans-(4-chlorophenyl)-7-aryl-6,7-dihydro-[1,3]dioxolo[4,5- f]benzofuran-6-yl)methanone in excellent yield and in short time.

Metal-Free Photoinduced Hydroalkylation Cascade Enabled by an Electron-Donor-Acceptor Complex

2020 ◽  
Author(s):  
José Tiago Menezes Correia ◽  
Gustavo Piva da Silva ◽  
Camila Menezes Kisukuri ◽  
Elias André ◽  
Bruno Pires ◽  
...  
Keyword(s):  
Electron Donor ◽  
Functional Group ◽  
Photoexcited Electron ◽  
One Pot ◽  
Quaternary Centers ◽  
Metal Free ◽  
Acceptor Complex ◽  
Catalyst Free ◽  
Donor Acceptor ◽  
Radical Cascade

A metal- and catalyst-free photoinduced radical cascade hydroalkylation of 1,7-enynes has been disclosed. The process is triggered by a SET event involving a photoexcited electron-donor-aceptor complex between NHPI ester and Hantzsch ester, which decomposes to afford a tertiary radical that is readily trapped by the enyne. <a>The method provides an operationally simple, robust and step-economical approach to the construction of diversely functionalized dihydroquinolinones bearing quaternary-centers. A sequential one-pot hydroalkylation-isomerization approach is also allowed giving access to a family of quinolinones. A wide substrate scope and high functional group tolerance was observed in both approaches</a>.

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.

scholarly journals Algal magnetic nickel oxide nanocatalyst in accelerated synthesis of pyridopyrimidine derivatives

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Javad Moavi ◽  
Foad Buazar ◽  
Mohammad Hosein Sayahi
Keyword(s):  
Nickel Oxide ◽  
Spherical Shape ◽  
Marine Macroalgae ◽  
Bet Surface Area ◽  
Nickel Oxide Nanoparticles ◽  
One Pot ◽  
Efficient Catalyst ◽  
Coating Agent ◽  
Synthesis Conditions ◽  
Nio Nps

AbstractThis research presents a novel biological route for the biosynthesis of nickel oxide nanoparticles (NiO NPs) using marine macroalgae extract as a reducing and coating agent under optimized synthesis conditions. XRD and TEM analyses revealed that phytosynthesized NiO NPs are crystalline in nature with a spherical shape having a mean particle size of 32.64 nm. TGA results indicated the presence of marine-derived organic constituents on the surface of NiO NPs. It is found that biogenic NiO NPs with BET surface area of 45.59 m2g−1 is a highly efficient catalyst for benign one-pot preparation of pyridopyrimidine derivatives using aqueous reaction conditions. This environmentally friendly procedure takes considerable advantages of shorter reaction times, excellent product yields (up to 96%), magnetically viable nanocatalyst (7 runs), low catalyst loadings, and free toxic chemical reagents.

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