scholarly journals Nano TiO2: An Efficient Catalyst for the Synthesis of Biscoumarins in Aqueous Medium

2014 ◽  
Vol 30 (2) ◽  
pp. 577-580 ◽  
Author(s):  
Hamide Babaei ◽  
Naser Montazeri
Keyword(s):  
Aqueous Medium ◽  
Nano Tio2 ◽  
Efficient Catalyst

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.

Synthesis of Trans-6-(4-Chlorobenzoyl)-7-(Aryl)-1,3-Dimethyl-6,7-Dihydrofuro[3,2-d]Pyrimidine-2,4-Diones Using Choline Hydroxide as an Efficient Catalyst in an Aqueous Medium

2017 ◽  
Vol 41 (3) ◽  
pp. 139-142 ◽  
Author(s):  
Maryam Salari ◽  
Alireza Hassanabadi ◽  
Mohammad H. Mosslemin
Keyword(s):  
Aqueous Medium ◽  
Aromatic Aldehyde ◽  
Reaction Times ◽  
Efficient Synthesis ◽  
One Pot ◽  
Efficient Catalyst ◽  
Excellent Yield ◽  
One Pot Condensation

A green and efficient synthesis of the trans-6-(4-chlorobenzoyl)-7-(aryl)-1,3-dimethyl-6,7-dihydrofuro[3,2-d]pyrimidine-2,4-diones has been achieved via a three-component, one-pot condensation of 2-[2-(4-chlorophenyl)-2-oxoethyl)]isoquinolinium bromide with 1,3-dimethylbarbituric acid and an aromatic aldehyde in the presence of catalytic amounts of choline hydroxide in water under reflux conditions. This gives trans-6-(4-chlorobenzoyl)-7-(aryl)-1,3-dimethyl-6,7-dihydrofuro[3,2-d]pyrimidine-2,4-diones in excellent yield and in short reaction times.

scholarly journals In situ Generated Ru(0)-HRO@Na-β From Hydrous Ruthenium Oxide (HRO)/Na-β: An Energy-Efficient Catalyst for Selective Hydrogenation of Sugars

2020 ◽  
Vol 8 ◽  
Author(s):  
Sreedhar Gundekari ◽  
Heena Desai ◽  
Krishnan Ravi ◽  
Joyee Mitra ◽  
Kannan Srinivasan
Keyword(s):  
Aqueous Medium ◽  
Reaction Temperature ◽  
Energy Efficient ◽  
Ruthenium Oxide ◽  
Green Process ◽  
Sugar Alcohols ◽  
Reaction Conditions ◽  
Efficient Catalyst ◽  
Hydrogenation Reactions

A green process for the hydrogenation of sugars to sugar alcohols was designed in aqueous medium using hydrous ruthenium oxide (HRO) as a pre-catalyst supported on Na-β zeolite. Under optimized reaction conditions, sugars such as xylose, glucose, and mannose converted completely to the corresponding sugar alcohols xylitol, sorbitol, and mannitol with 100% selectivity. The pre-catalyst (HRO) is converted in situ to active Ru(0) species during the reaction under H2, which is responsible for the hydrogenation. The catalyst was recyclable up to five cycles with no loss in activity. The reduction of HRO to the active Ru(0) species is dependent on the reaction temperature and H2 pressure. Ru(0) formation increased and consequently an increased hydrogenation of sugars was observed with an increase in reaction temperature and hydrogen pressure. Further, in situ generation of Ru(0) from HRO was assessed in different solvents such as water, methanol, and tetrahydrofuran; aqueous medium was found to be the most efficient in reducing HRO. This work further demonstrates the use of supported HRO as an efficient pre-catalyst for biomass-based hydrogenation reactions.

ChemInform Abstract: A New Domino Knoevenagel-hetero-Diels-Alder Reaction: An Efficient Catalyst-Free Synthesis of Novel Thiochromone-Annulated Thiopyranocoumarin Derivatives in Aqueous Medium.

ChemInform ◽  
2011 ◽  
Vol 42 (8) ◽  
pp. no-no
Author(s):  
Firouz Matloubi Moghaddam ◽  
Mostafa Kiamehr ◽  
Mohammad Reza Khodabakhshi ◽  
Zohreh Mirjafary ◽  
Shaghayegh Fathi ◽  
...  
Keyword(s):  
Aqueous Medium ◽  
Alder Reaction ◽  
Diels Alder ◽  
Efficient Catalyst ◽  
Catalyst Free ◽  
Diels Alder Reaction
Sign in / Sign up

Export Citation Format

Share Document