Versatile Synthesis of Functionalized Tetrahydroisoquinolines by Ring Transformation of 2H-Pyran-2-ones

2019 ◽  
Vol 72 (7) ◽  
pp. 524 ◽  
Author(s):  
Priyanka B. Kole ◽  
Fateh V. Singh

Functionalized tetrahydroisoquinolines are convenient precursors for the construction of numerous heterocyclic compounds of therapeutic importance. In this paper we have illustrated an efficient synthesis of highly substituted tetrahydroisoquinolines from 2H-pyran-2-ones via nucleophile-mediated ring transformation with tert-butyl-4-oxopiperidine-1-carboxylate followed by acid-mediated cleavage of the tert-butyloxycarbonyl group. The products were achieved smoothly in high yields with flexibility of various substituents.

1988 ◽  
Vol 53 (11) ◽  
pp. 2778-2786 ◽  
Author(s):  
Leif Grehn ◽  
Ulf Ragnarsson

An efficient synthesis of benzyl tert-butyl iminodicarbonate (IV), starting from benzoyl isocyanate, is reported. Reaction of the isocyanate with benzyl alcohol gave benzyl N-benzoylcarbamate (II) which on exhaustive tert-butoxycarbonylation via the non-isolated triacyl amine III, after aminolysis, provided the title compound. The sodium salt V was alkylated with various halides under Gabriel conditions to give in high yields the corresponding benzyloxycarbonyl tert-butoxycarbonyl diprotected amines. Similarly, compound IV was alkylated with alcohols under Mitsunobu conditions to give some additional amines of this type, from which the protecting groups can be removed selectively under mild conditions.


2020 ◽  
Vol 17 ◽  
Author(s):  
Kalyani K. ◽  
Srinivasa Reddy Kallam

Abstract:: An efficient synthesis of 2-substituted Quinazolin-4(3H)-ones has been developed from isatoic anhydride with various amidoximes by using recyclable polymer supported sulphonic acid catalyst. Excellent functional group compatibil-ity and high yields are the important features of this protocol.


1999 ◽  
Vol 23 (6) ◽  
pp. 368-369
Author(s):  
Issa Yavari ◽  
Abbas Ali Esmaili ◽  
Sakineh Asghari ◽  
Hamid Reza Bijanzadeh

The highly reactive 1:1 intermediate produced in the reaction between tert-butyl isocyanide and dialkyl acetylenedicarboxylates is trapped by dialkyl 2-bromomalonates to yield the title compounds in fairly high yields.


Tetrahedron ◽  
2001 ◽  
Vol 57 (39) ◽  
pp. 8349-8356 ◽  
Author(s):  
Vijay Nair ◽  
Bini Mathew ◽  
Nigam P Rath ◽  
M Vairamani ◽  
S Prabhakar

2011 ◽  
Vol 7 ◽  
pp. 1334-1341 ◽  
Author(s):  
Sanny Verma ◽  
Suman L Jain ◽  
Bir Sain

PEG-embedded potassium tribromide ([K+PEG]Br3 −) was found to be an efficient and recyclable catalyst for the synthesis of functionalized piperidines in high yields in a one step, three component coupling between aldehyde, amine and β-keto ester. At the end of the reaction the [K+PEG]Br3 − was readily regenerated from the reaction mixture by treating the residue containing [K+PEG]Br− with molecular bromine.


2021 ◽  
Vol 25 ◽  
Author(s):  
Neda Reihani ◽  
Hamzeh Kiyani

: An efficient synthesis of 4-arylidene-3-alkylisoxazole-5(4H)-ones has been implemented via the three-component cyclocondensation of aryl(heteroaryl)aldehydes with hydroxylamine hydrochloride and β-ketoesters. The potassium 2,5-dioxoimidazolidin-1-ide has been introduced as the new organocatalyst to facilitate of this heterocyclization. In the current process, three starting materials, including substituted benzaldehydes/heterocyclic aromatic aldehydes, hydroxylamine hydrochloride, and ethyl acetoacetate/propyl acetoacetate/butyryl acetoacetate have been successfully used for the synthesize of the number of substituted isoxazole-5(4H)-ones in good to high yields in ethylene glycol as a green reaction medium at 80 ºC. The low catalyst loading is also a main advantage over the some reported catalysts.


Molecules ◽  
2018 ◽  
Vol 23 (11) ◽  
pp. 3031 ◽  
Author(s):  
Xiaodong Tang ◽  
Songlei Zhu ◽  
Ying Ma ◽  
Ren Wen ◽  
Lanqi Cen ◽  
...  

A green, convenient and tandem procedure for the efficient synthesis of highly substituted indeno[1,2-b]pyrrole and acenaphtho[1,2-b]pyrrole derivatives by domino three-component reaction of tryptamine/benzylamine, 1,3-dicarbonyl compounds and ninhydrin/ acenaphthenequinone is described. The significant features of this procedure were characterized by mild reaction conditions, high yields, operational simplicity and it being environmentally benign.


Synthesis ◽  
2017 ◽  
Vol 49 (16) ◽  
pp. 3662-3669 ◽  
Author(s):  
Xiao-Yu Zhou ◽  
Xia Chen ◽  
Liang-Guang Wang ◽  
Dan Yang ◽  
Zhi Li

The palladium-catalyzed oxidation-hydroxylation and oxidation-methoxylation of N-Boc indoles for the synthesis of tert-butyl 2-hydroxy(methoxy)-3-oxoindoline-1-carboxylates and their derivatives is developed. The process occurs readily using PdCl2 as the catalyst and acetonitrile as the solvent to afford 3-oxoindolines in moderate to high yields. A mechanism for this Pd-catalyzed oxidation-hydroxylation and oxidation-methoxylation of N-Boc indoles is proposed.


2019 ◽  
Vol 10 (2) ◽  
pp. 166-170 ◽  
Author(s):  
Fatma Ahmed Abo Elsoud ◽  
Mohamed Abd-Elmonem ◽  
Mohamed Abo Elsebaa ◽  
Kamal Usef Sadek

Efficient synthesis of non-annulated 2-amino-4H-pyrans and 2-amino-8-oxo-4,8-dihydropyrano[3,2-b]pyran derivatives, which are biologically relevant heterocycles is achieved, utilizing a domino three-component reaction of ethyl acetoacetate or kojic acid with aromatic aldehydes and malononitrile catalyzed by Zn(L-proline)2 as reusable organometallic catalyst. The process exhibits high atom economy, short reaction time, simple work up, high yields and environmentally friendly nature. Excellent yields of the targeted molecules have been obtained.


RSC Advances ◽  
2016 ◽  
Vol 6 (59) ◽  
pp. 54495-54502 ◽  
Author(s):  
Nataraj Poomathi ◽  
Paramasivan T. Perumal

A simple and efficient metal-free methodology for the synthesis of β-nitroolefins has been developed from arylidinemalononitrile using bifunctional cinchona alkaloid along with di-tert-butyldicarbonate–DMAP in high yields with total selectivity.


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