Nelson Nascimento - Academia.edu (original) (raw)
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Papers by Nelson Nascimento
ChemistrySelect, 2017
The use of Et 2 NH as organocatalyst for 1,3-dipolar cycloadditions of 3-azido-2-organylselanyl-p... more The use of Et 2 NH as organocatalyst for 1,3-dipolar cycloadditions of 3-azido-2-organylselanyl-pyridines with 1,3dicarbonyl compounds is reported in this work. Reactions were conducted using DMSO as solvent at room temperature in air. All products were obtained in good to excellent yields. The reaction took place under very mild conditions and tolerated a range of functionalities. 1-(2-(Phenylselanyl)pyridin-3-yl)-1H-1,2,3-triazole-4-carboxylate containing an alkyne substituent was selected as candidate for a Cu-catalyzed azide alkyne cycloaddition reaction, affording the bis-triazole in good yields.
![Research paper thumbnail of Ultrasound-assisted synthesis of imidazo[1,2-a]pyridines and sequential one-pot preparation of 3-selanyl-imidazo[1,2-a]pyridine derivatives](https://attachments.academia-assets.com/110898020/thumbnails/1.jpg)
](Arkivoc, 2019
A simple and rapid method to synthesize imidazo[1,2-a]pyridines starting from 2-aminopyridine and... more A simple and rapid method to synthesize imidazo[1,2-a]pyridines starting from 2-aminopyridine and 2bromoacetophenone derivatives under ultrasonic irradiation was developed. This protocol tolerates a wide range of 2-bromoacetophenone derivatives to produce a variety of imidazo[1,2-a]pyridines in good to excellent yields. Additionally, the one-pot preparation of 3-(organylselanyl)imidazo[1,2-a]pyridines via a sequential method is presented. In this case, different diorganyl diselenides were used as starting material s to afford the corresponding coupling products in excellent yields and short reaction times under sonication. The reactions were conducted in PEG-400, a cheap and nontoxic solvent, compatible with the ultrasound conditions in an environmentally benign process.
ChemistrySelect, 2017
The use of Et 2 NH as organocatalyst for 1,3-dipolar cycloadditions of 3-azido-2-organylselanyl-p... more The use of Et 2 NH as organocatalyst for 1,3-dipolar cycloadditions of 3-azido-2-organylselanyl-pyridines with 1,3dicarbonyl compounds is reported in this work. Reactions were conducted using DMSO as solvent at room temperature in air. All products were obtained in good to excellent yields. The reaction took place under very mild conditions and tolerated a range of functionalities. 1-(2-(Phenylselanyl)pyridin-3-yl)-1H-1,2,3-triazole-4-carboxylate containing an alkyne substituent was selected as candidate for a Cu-catalyzed azide alkyne cycloaddition reaction, affording the bis-triazole in good yields.
Arkivoc, 2019
A simple and rapid method to synthesize imidazo[1,2-a]pyridines starting from 2-aminopyridine and... more A simple and rapid method to synthesize imidazo[1,2-a]pyridines starting from 2-aminopyridine and 2bromoacetophenone derivatives under ultrasonic irradiation was developed. This protocol tolerates a wide range of 2-bromoacetophenone derivatives to produce a variety of imidazo[1,2-a]pyridines in good to excellent yields. Additionally, the one-pot preparation of 3-(organylselanyl)imidazo[1,2-a]pyridines via a sequential method is presented. In this case, different diorganyl diselenides were used as starting material s to afford the corresponding coupling products in excellent yields and short reaction times under sonication. The reactions were conducted in PEG-400, a cheap and nontoxic solvent, compatible with the ultrasound conditions in an environmentally benign process.