scholarly journals Highly Efficient and Diastereoselective Construction of Substituted Pyrrolidines Bearing A Quaternary Carbon Center via 1,3-Dipolar [3 + 2] Cycloaddition

2021 ◽  
Author(s):  
Kaikai wang ◽  
Yanli Li ◽  
Yingchao Zhao ◽  
Aili sun ◽  
Rongxiang Chen ◽  
...  
Keyword(s):  
Efficient Method ◽  
Azomethine Ylides ◽  
Dipolar Cycloaddition ◽  
Quaternary Carbon ◽  
Reaction Conditions ◽  
Highly Efficient ◽  
High Yields

A general approach to substituted pyrrolidines via [3 + 2] 1,3-dipolar cycloaddition between nonstabilized azomethine ylides and cyanosulfones was developed. The efficient method provides a series of substituted pyrrolidines bearing a quaternary carbon center in high yields (up to 98%) excellent diastereoselectivities (up to >25:1 dr) under ambient reaction conditions.

Copper/GanPhos-Catalyzed 1,3-Dipolar Cycloaddition of Azo­methine Ylides: An Efficient Access to Chiral Pyrrolidine Spirocycles

Synthesis ◽  
2020 ◽  
Author(s):  
Zhenjie Gan ◽  
Er-Qing Li ◽  
Ke Li ◽  
Hui Zhang
Keyword(s):  
Optically Active ◽  
Azomethine Ylides ◽  
Dipolar Cycloaddition ◽  
Reaction Conditions ◽  
Highly Efficient ◽  
Efficient Access ◽  
Stereogenic Centers

AbstractA highly efficient copper/GanPhos-catalyzed 1,3-dipolar cyclo­addition­ of azomethine ylides is reported. This viable transformation provides a series of optically active spiro[dihydronaphthalene-2,3′-pyrrolidine]s, bearing one spiro quaternary and three tertiary stereogenic centers, in good yields and with high ee values. This protocol features high diastereo- and enantioselectivity, broad substrate scope and mild reaction conditions.

Squaramide-Catalyzed Asymmetric Michael/Cyclization Cascade Reaction of Unsaturated Thiazolidinones and 3-Isothiocyanato Oxindoles: Synthesis of New Bispirocyclic Heterocycles

Synthesis ◽  
2018 ◽  
Vol 50 (07) ◽  
pp. 1535-1545 ◽  
Author(s):  
Da-Ming Du ◽  
Yong-Xing Song
Keyword(s):  
Efficient Method ◽  
Cascade Reaction ◽  
Reaction Conditions ◽  
Highly Efficient ◽  
Chiral Centers ◽  
High Yields

A highly efficient method for the construction of oxindole-pyrrolidone-thiazolidinone bispirocyclic heterocycles bearing three contiguous chiral centers including two quaternary one via a Michael/cyclization cascade reaction has been developed. Using bifunctional cinchona-derived squaramide as catalyst, the reactions of 3-isothio­cyanato oxindoles with unsaturated thiazolidinone derivatives proceeded smoothly under mild reaction conditions to afford a series of complex chiral oxindole-pyrrolidone-thiazolidinone bispirocyclic heterocycles in high yields (up to 99%) with excellent diastereo- and enantioselectivities (up to >99:1 dr, >99% ee).

Novel One-pot Synthesis of Pyranocarbazole Derivatives via an Isocyanide-based Three-component Reaction

2020 ◽  
Vol 17 ◽  
Author(s):  
Visarapu Malathi ◽  
Pedavenkatagari Narayana Reddy ◽  
Pannala Padmaja
Keyword(s):  
Efficient Method ◽  
Atom Economy ◽  
Reaction Conditions ◽  
One Pot ◽  
Catalyst Free ◽  
One Pot Synthesis ◽  
Three Component Reaction ◽  
High Yields

Abstract:: An efficient method has been developed for the synthesis of new pyrano[3,2-c] and pyrano[3,2-a]carbazole de-rivatives via a three component reaction of 4-hydroxycarbazole or 2-hydroxycarbazole, isocyanides, and dialkylacetylenedi-carboxylates. Noteworthy features of this protocol include mild reaction conditions, catalyst-free, high atom-economy and high yields.

scholarly journals Cu(ii)/DM-Segphos catalyzed asymmetric 1,3-dipolar cycloaddition of benzoisothiazole-2,2-dioxide-3-ylidenes and azomethine ylides

RSC Advances ◽  
2017 ◽  
Vol 7 (18) ◽  
pp. 10816-10820 ◽  
Author(s):  
Feifei Li ◽  
Guorui Cao ◽  
Yanfeng Gao ◽  
Dawei Teng
Keyword(s):  
Azomethine Ylides ◽  
Dipolar Cycloaddition ◽  
High Yields

Cu(OTf)2/DM-Segphos catalyzed asymmetric 1,3-dipolar cycloaddition of benzoisothiazole-2,2-dioxide-3-ylidenes and azomethine ylides was studied. The spiropyrrolidinyl-benzoisothiazolines were obtained in high yields with up to >99 : 1 dr and 99% ee.

Synthesis of 4-arylethyl-6-arylpyrimidine-2-thiols through aza-Michael addition/nucleophilic addition/aromatization tandem reactions

2018 ◽  
Vol 24 (1) ◽  
pp. 23-26
Author(s):  
Zheng Li ◽  
Wenli Song ◽  
Jiaojiao He ◽  
Yan Du ◽  
Jingya Yang
Keyword(s):  
Efficient Method ◽  
Michael Addition ◽  
Nucleophilic Addition ◽  
Tandem Reactions ◽  
Reaction Conditions ◽  
High Yields ◽  
Work Up

Abstract An efficient method for the synthesis of the title compounds by reactions of divinyl ketones with thiourea is described. This protocol has the advantages of high yields, mild reaction conditions and simple work-up procedure.

Decarboxylative-Mediated Regioselective 1,3-Dipolar Cycloaddition for Diversity-Oriented Synthesis of Structurally exo′-Selective Spiro[oxindole-pyrrolidine-dihydrocoumarin] Hybrids

Synthesis ◽  
2020 ◽  
Author(s):  
Ying Zhou ◽  
Xiong-Wei Liu ◽  
Shun-Qin Chang ◽  
Qi-Lin Wang ◽  
Shuang Chen ◽  
...  
Keyword(s):  
Carboxylic Acid ◽  
Transition State ◽  
Azomethine Ylides ◽  
Dipolar Cycloaddition ◽  
Diversity Oriented Synthesis ◽  
Biologically Relevant ◽  
Good Substrate ◽  
Quaternary Center ◽  
Substrate Tolerance ◽  
High Yields

A general and practical three-component regioselective 1,3-dipolar cycloaddition of 3-amino-oxindole-based azomethine ylides and coumarins has been developed. This reaction displayed good substrate tolerance and gave a diverse array of biologically relevant spiro[ox-­i­ndole-pyrrolidine-dihydrocoumarin] derivatives bearing four contiguous stereocenters including one spiro quaternary center in moderate to high yields (up to 90%) with high diastereoselectivities (up to 15:1 dr). It is based on the application of carboxylic acid activated coumarins as dienophiles followed by a decarboxylation process. The possible mechanism of the 1,3-dipolar cycloaddition is proposed via an exo′-transition state. Furthermore, this is the first example of decarboxylative-mediated regioselective 1,3-dipolar cycloaddition of 3-amino-oxindole-based azomethine ylides and coumarins.

Copper(II)-Promoted Oxidation/[3+2]Cycloaddition/Aromatization Cascade: Efficient Synthesis of Tetrasubstituted NH-Pyrrole from Chalcones and Iminodiacetates

Synlett ◽  
2019 ◽  
Vol 30 (12) ◽  
pp. 1442-1446 ◽  
Author(s):  
Zhang-qi Lin ◽  
Chao-dong Li ◽  
Zi-chun Zhou ◽  
Shuai Xue ◽  
Jian-rong Gao ◽  
...  
Keyword(s):  
Efficient Method ◽  
Cascade Reaction ◽  
Oxidative Cyclization ◽  
Efficient Synthesis ◽  
Reaction Conditions ◽  
Highly Efficient ◽  
Wide Range ◽  
Reaction Proceeds

A simple and highly efficient method for the preparation of tetrasubstituted NH-pyrrole from a wide range of chalcones and diethyl iminodiacetates via a Cu(OAc)2-promoted oxidation/[3+2]cycloaddition/aromatization cascade reaction has been developed. This reaction proceeds through dehydrogenations, deamination, and oxidative cyclization, affording the corresponding products in good to excellent yields. This convenient methodology for constructing tetrasubstituted NH-pyrroles has several advantages over existing methods, such as the use of easily accessible chalcones and readily available diethyl iminodiacetates, and mild reaction conditions. A wide range of substrates are tolerated.

Concise Synthesis of Tryptanthrin Spiro Analogues with In Vitro Antitumor Activity Based on One-Pot, Three-Component 1,3-Dipolar Cycloaddition of Azomethine Ylides to Сyclopropenes

Synthesis ◽  
2018 ◽  
Vol 51 (03) ◽  
pp. 713-729 ◽  
Author(s):  
Vitali Boitsov ◽  
Alexander Stepakov ◽  
Alexander Filatov ◽  
Nickolay Knyazev ◽  
Stanislav Shmakov ◽  
...  
Keyword(s):  
Antitumor Activity ◽  
Azomethine Ylides ◽  
Azomethine Ylide ◽  
Dipolar Cycloaddition ◽  
One Pot ◽  
Economic Method ◽  
Reaction Proceeds ◽  
High Yields

A simple, efficient and atom-economic method has been developed for the synthesis of complex alkaloid-like compounds with spiro-fused indolo[2,1-b]quinazoline and cyclopropa[a]pyrrolizine or 3-azabicyclo[3.1.0]hexane moieties. We have found that one-pot, three-component 1,3-dipolar cycloaddition reactions allow the desired products to be obtained from various cyclopropene derivatives with tryptanthrin-derived azomethine ylides generated in situ, in good to high yields and excellent diastereoselectivity. The possibility of ylide generation was exemplified by using α-amino acids (l-proline, l-4-thiazolidincarboxylic acid) and simplest peptides (dipeptide Gly-Gly, tripeptide Gly-Gly-Gly). Quantum chemical investigations indicate that the reaction proceeds through the S-shaped azomethine ylide, the interaction of which with cyclopropenes proceeds via a less sterically hindered endo-transition state. The antitumor activity of some of spiro-tryptanthrin derivatives against erythroleukemia (K562), cervical carcinoma (HeLa) and colon carcinoma (CT26) cell lines was evaluated in vitro by MTS-assay.

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