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).

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.

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.

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.

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.

A clean, simple and efficient synthesis of trans-[3-(aryl)-2,3-dihydrofuro[3,2-h] quinolin-2-yl]-(4-chlorophenyl)methanones

2017 ◽  
Vol 41 (7) ◽  
pp. 380-383
Author(s):  
Maryam Salari ◽  
Alireza Hassanabadi ◽  
Mohammad H. Mosslemin
Keyword(s):  
Reaction Time ◽  
Green Chemistry ◽  
Aromatic Aldehyde ◽  
Efficient Method ◽  
Efficient Synthesis ◽  
Reaction Conditions ◽  
Short Reaction Time ◽  
High Yields

We report a green and efficient method for the synthesis of trans-[3-(aryl)-2,3-dihydrofuro[3,2- h]quinolin-2-yl]-(4-chlorophenyl) methanones from the condensation of 2-[2-(4-chlorophenyl)-2-oxoethyl)]isoquinolinium bromide with 8-hydroxyquinoline and an aromatic aldehyde in the presence of catalytic amounts of choline hydroxide in water at reflux conditions. This new protocol employing choline hydroxide, which is a green and inexpensive catalyst, offers advantages such as mild reaction conditions, short reaction time, high yields and does not involve any hazardous solvent. Therefore, this procedure can be classified as green chemistry.

Transition-Metal-Free Synthesis of Trifluoromethylated Furans via a Bu3P-Mediated Tandem Acylation–Wittig Reaction

Synlett ◽  
2020 ◽  
Vol 31 (20) ◽  
pp. 2035-2038
Author(s):  
Wei Zhou ◽  
Maizhan Li
Keyword(s):  
Transition Metal ◽  
Functional Groups ◽  
Nucleophilic Addition ◽  
Wittig Reaction ◽  
Reaction Conditions ◽  
Metal Free ◽  
Highly Efficient ◽  
Intramolecular Wittig Reaction ◽  
High Yields

AbstractA highly efficient nucleophilic addition–O-acylation–intramolecular Wittig reaction of β-trifluoromethyl α,β-enones is disclosed. This strategy features mild reaction conditions and provides a practical transition-metal-free method to a set of biologically significant trifluoromethylated furans in high yields with diverse functional groups.

scholarly journals Solvent-Free Green and Efficient One-Pot Synthesis of Dihydropyrano[3,2-c]chromene Derivatives

2013 ◽  
Vol 2013 ◽  
pp. 1-5 ◽  
Author(s):  
Shubha Jain ◽  
Deepika Rajguru ◽  
Balwant S. Keshwal ◽  
Aman D. Acharya
Keyword(s):  
Efficient Method ◽  
Present Method ◽  
Reaction Times ◽  
Aromatic Aldehydes ◽  
Solvent Free ◽  
Reaction Conditions ◽  
One Pot ◽  
Highly Efficient ◽  
One Pot Synthesis

A rapid, clean, and highly efficient method for synthesis of dihydropyrano[3,2-c]chromene derivatives by one-pot, three-component condensation of aromatic aldehydes, malononitrile, and 4-hydroxycoumarin using DABCO as catalyst in solvent-free neat conditions is described. The present method has the advantages of mild reaction conditions, short reaction times, easy isolation of products, and excellent yields.

Al(OTf)3 — A highly efficient catalyst for the tetrahydropyranylation of alcohols under solvent-free conditions

2008 ◽  
Vol 86 (12) ◽  
pp. 1099-1104 ◽  
Author(s):  
Ahmed Kamal ◽  
M Naseer A Khan ◽  
Y VV Srikanth ◽  
K Srinivasa Reddy
Keyword(s):  
Comparative Study ◽  
Efficient Method ◽  
Catalytic Amount ◽  
Solvent Free ◽  
Molar Ratio ◽  
Reaction Conditions ◽  
Efficient Catalyst ◽  
Highly Efficient ◽  
Solvent Free Conditions ◽  
The Comparative Study

A simple and highly efficient method has been developed for the tetrahydropyranylation of alcohols by their reaction with 3,4-dihydro-2H-pyran (DHP) using a catalytic amount (0.01–1 mol%) of aluminium triflate under solvent-free conditions. The effect of various factors like temperature, amount of the catalyst, and molar ratio of substrates on the reaction conditions has also been studied. The comparative study of tetrahydropyranylation of benzyl alcohol using various catalysts including some reported ones shows the efficiency of this catalyst.Key words: tetrahydropyranylation, aluminium triflate, alcohols, catalysis.

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