Solvent-Free, Microwave-Assisted Conversion of Tosylates into Iodides

2014 ◽  
Vol 67 (9) ◽  
pp. 1360 ◽  
Author(s):  
Jia Cao ◽  
Patrick Perlmutter

A highly efficient method for the conversion of primary tosylates into the corresponding iodides is outlined. The method involves heating a neat mixture of the tosylate and solid sodium iodide in a microwave cavity. Reaction times are short, usually about 60 minutes, delivering high yields. This procedure is especially useful for the in situ generation of volatile primary iodides, and for most of the primary iodides, the crude product is sufficiently pure.

2018 ◽  
Vol 42 (12) ◽  
pp. 604-607
Author(s):  
Loghman Firoozpour ◽  
Hoda Yahyavi ◽  
Ramona Ejtemaei ◽  
Setareh Moghimi ◽  
Alireza Foroumadi

A green and efficient method for preparing novel heterocyclic systems is established through the reaction of differently substituted benzaldehydes, barbituric acid and 4-amino-2H-chromene-2-one under solvent-free conditions. This method affords 6H-chromeno[3’,4’:5,6] pyrido[2,3-d]pyrimidine-trione derivatives in high yields and short reaction times.


2005 ◽  
Vol 83 (3) ◽  
pp. 260-265 ◽  
Author(s):  
Surinderjit Singh ◽  
M PS Ishar ◽  
Gajendra Singh ◽  
Rajinder Singh

Contrary to literature reports, the o-allyloxy- and crotyloxy-acetophenone-oximes (2a, 2b) are transformed to nitrones, which undergo regio- and stereoselective intramolecular 1,3-dipolar cycloadditions, both on microwave heating under solvent free conditions and refluxing in toluene, to afford novel cycloadducts (5a, 5b); the oxazepine-N-oxide (3a) reported to be formed in 98% yield was obtained only as a minor product (~10%). However, o-cinnamyloxy-acetophenone-oxime (2c) under similar conditions undergoes intramolecular N-alkylation to afford nitrone (3c). The reactions carried out under microwave irradiation are cleaner, require shorter reaction times, and have higher yields. Corresponding intramolecular 1,3-dipolar cycloadditions of N-methylnitrones (B), generated in situ from o-alkenylmethoxy-acetophenones (1a–1c) and N-methylhydroxylamine under solvent-free microwave irradiation conditions, are completely regio- and stereoselective, require much shorter reaction times, and afford adducts (4a–4c) in higher yields, as compared with their thermal counterparts.Key words: cycloadditions, nitrones, oximes, o-alkenylmethoxy-acetophenones, microwave, isoxazolidines.


2021 ◽  
Vol 76 (2) ◽  
pp. 85-90
Author(s):  
Abdolkarim Zare ◽  
Manije Dianat

Abstract A highly efficient and green protocol for the synthesis of pyrimido[4,5-b]quinolines has been described. The one-pot multicomponent reaction of dimedone with arylaldehydes and 6-amino-1,3-dimethyluracil in the presence of N,N-diethyl-N-sulfoethanaminium chloride ([Et3N–SO3H][Cl]) as an ionic liquid (IL) catalyst under solvent-free conditions afforded the mentioned compounds in high yields and short reaction times. Our protocol is superior to many of the reported protocols in terms of two or more of these factors: the reaction times, yields, conditions (solvent-free versus usage of organic solvents), temperature and catalyst amount.


ChemInform ◽  
2011 ◽  
Vol 43 (1) ◽  
pp. no-no
Author(s):  
Thomas O. Painter ◽  
Paul D. Thornton ◽  
Mario Orestano ◽  
Conrad Santini ◽  
Michael G. Organ ◽  
...  

2016 ◽  
Vol 40 (12) ◽  
pp. 10300-10304 ◽  
Author(s):  
Raktani Bikshapathi ◽  
Parvathaneni Sai Prathima ◽  
Vaidya Jayathirtha Rao

An efficient, eco-friendly protocol for selective oxidation of primary and secondary Baylis–Hillman alcohols to the corresponding carbonyl compounds in high yields has been developed with 2-iodosobenzoic acid (IBA).


2005 ◽  
Vol 2005 (11) ◽  
pp. 733-735 ◽  
Author(s):  
Nemai C. Ganguly ◽  
Sanjoy Dutta ◽  
Mrityunjoy Datta ◽  
Prithwiraj De

Predominant ortho-selective mononitration of low-melting and liquid phenols and hydroxycoumarins in moderate to high yields has been accomplished upon grinding with solid cerium (IV) ammonium nitrate (CAN). Microwave-assisted expeditious CAN-mediated nitration of relatively high melting phenols and hydroxycoumarins with high efficiency and selectively under solvent-free conditions has been also developed to address the problems of sluggishness and low yield for these reluctant substrates.


2021 ◽  
Vol 18 ◽  
Author(s):  
Abolfazl Olyaei ◽  
Zahra Ghahremany ◽  
Madieh Sadeghpour

: A green and efficient protocol was developed for the one-pot three-component synthesis of novel 2-(4-hydroxy-2-oxo-2H-chromen-3-yl)-2-(arylamino)-1H-indene-1,3(2H)-dione derivatives by the reaction of 4-hydroxycoumarin, ninhydrin and aromatic amines in the presence of guanidine hydrochloride as an organocatalyst under solvent-free conditions. The present approach offers several advantages such as low cost, simple work-up, short reaction times, chromatography-free purification, high yields and greener conditions.


2021 ◽  
Author(s):  
Mojgan Zendehdel ◽  
Fatemeh Tavakoli

Abstract A new class of catalyst has been prepared with sulfunic acid functionalized HY zeolite (HY-N-SO3H) and characterized by FESEM, TEM, FTIR, TGA, XRD and BET. The result show that the catalyst has the micro-meso structure without ordering in the mesophase. Then, two sets of organic reaction were examined to consider of catalytic activity. The micro-meso structure HY-N-SO3H was used as an acidic catalyst to synthesis of coumarins via Pechmann reaction and facile transformation of amines to formamides under solvent free condition. This catalyst was compared with NaY-N-SO3H and MCM-N-SO3H and pure porous material to consider of the effect of acidity and kind and size of porous in the catalyst. The significant advantages of HY-N-SO3H respect to other catalyst are short reaction times, high yields, pure products, mild conditions and easy workup. In addition, we report an original and environmentally friendly solvent-free procedures which reusability of catalyst makes this method nearly green and environmental friendly.


2021 ◽  
Author(s):  
Vijayshekar pulusu ◽  
Chinna Rajanna Rajanna Kamatala ◽  
Anil Kumar Mardhanpally ◽  
Hemanth Sriram Yel ◽  
Yaku Guguloth ◽  
...  

Abstract Silica supported nanogreenacids like Si-KHSO4, and Si-HClO4are explored as reusable catalysts for bromination of aromatic and hetero aromatic compounds using KBr under solvothermal, and solvent-free conditions. Reaction times reduced from Reacions under conventional solvothermal protocols conditions required (4 – 6) hours, while ultrasonic assisted reactions only (9 – 12) minutes for completion. But, solvent-free microwave assisted reactions required only (1-5) minutes exhibiting striking rate acceleration compared to the solvothermal and ultrasonic assisted protocols All the reaction protocols afforded fairly good yields of brominated products, which are comparable with existing protocols.


Synlett ◽  
2018 ◽  
Vol 29 (15) ◽  
pp. 2015-2018 ◽  
Author(s):  
William Wulff ◽  
Xin Zhang ◽  
Yijing Dai

An efficient method was developed for the synthesis of α-amino ketones from α-hydroxy imines. The reaction occurs through an α-iminol rearrangement involving the migration of a substituent of the carbinol carbon to the imine carbon. The optimal catalysts were found to be silica gel or montmorillonite K 10, which effected migration of a variety of aryl and alkyl substituents in high yields. The rearrangement can also be carried out on imines generated in situ from aldehydes and amines in essentially the same yields as those from the preformed imines.


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