A highly efficient asymmetric synthesis of quaternary stereocenter-containing indolizidine and quinolizidine alkaloids using aldehydes, nitroalkenes, and unactivated cyclic ketimines

2014 ◽  
Vol 50 (100) ◽  
pp. 15913-15915 ◽  
Author(s):  
Yu Tan ◽  
Yong-Jian Chen ◽  
Hua Lin ◽  
Han-Lin Luan ◽  
Xing-Wen Sun ◽  
...  
Keyword(s):  
Asymmetric Synthesis ◽  
Quinolizidine Alkaloids ◽  
One Pot ◽  
Efficient Approach ◽  
Highly Efficient ◽  
Quaternary Stereocenter

A highly efficient approach to the construction of indolizidines and quinolizidines bearing a bridged quaternary stereocenter has been established in a one-pot fashion using aldehydes, nitroalkenes, and cyclic ketimines.

scholarly journals A novel application of 2-silylated 1,3-dithiolanes for the synthesis of aryl/hetaryl-substituted ethenes and dibenzofulvenes

2017 ◽  
Vol 13 ◽  
pp. 1900-1906 ◽  
Author(s):  
Grzegorz Mlostoń ◽  
Paulina Pipiak ◽  
Róża Hamera-Fałdyga ◽  
Heinz Heimgartner
Keyword(s):  
Equimolar Amount ◽  
One Pot ◽  
Efficient Approach ◽  
Highly Efficient ◽  
High Yields

Trimethylsilyldiazomethane (TMS-CHN2) reacts readily with hetaryl thioketones to give sterically crowded 2-trimethylsilyl-4,4,5,5-tetrahetaryl-1,3-dithiolanes with complete regioselectivity at −75 °C as well as at rt. Thiofluorenone, a relatively stable and highly reactive aryl thioketone, yields upon treatment with TMS-CHN2 at −60 °C the corresponding 1,3,4-thiadiazoline. This unstable cycloadduct undergoes decomposition at ca. −45 °C and the silylated thiocarbonyl S-methanide generated thereby is trapped with complete regioselectivity by aryl or hetaryl thioketones forming also sterically crowded 2-trimethylsilyl-1,3-dithiolanes. The obtained 1,3-dithiolanes, by treatment with an equimolar amount of TBAF in a one-pot procedure, are converted in high yields into hetaryl/aryl-substituted ethenes or dibenzofulvenes, respectively, via a cycloreversion reaction of the intermediate 1,3-dithiolane carbanion. The presented protocol offers a new, highly efficient approach to tetrasubstituted ethenes and dibenzofulvenes bearing aryl and/or hetaryl substituents.

SnCl4 or TiCl4: highly efficient catalysts for the detetrahydropyranylation and demethoxymethylation of phenolic ethers and sequential one-pot asymmetric synthesis of 3-aryl-2-hydroxy-2,3-dihydroindan-1-ones from chalcone epoxides

RSC Advances ◽  
2015 ◽  
Vol 5 (77) ◽  
pp. 63095-63103 ◽  
Author(s):  
Naseem Ahmed ◽  
Gulab Khushalrao Pathe ◽  
Sohan Jheeta
Keyword(s):  
Asymmetric Synthesis ◽  
Reaction Conditions ◽  
One Pot ◽  
Highly Efficient

SnCl4 or TiCl4 catalysts provide a rapid and efficient detetrahydropyranylation and demethoxymethylation of phenolic ethers and a sequential one-pot intramolecular Friedel–Crafts alkylation of chalcone epoxides under mild reaction conditions.

scholarly journals A Highly Efficient Approach to the Synthesis of Complex α-Glycosyl Phosphosaccharides

2021 ◽  
Author(s):  
Yugen Zhu ◽  
Xiaojuan Zhang ◽  
Yutong Yang ◽  
Jiahao Ding ◽  
Yun Zhao ◽  
...  
Keyword(s):  
Phosphoric Acid ◽  
Leishmania Donovani ◽  
One Pot ◽  
Efficient Approach ◽  
Highly Efficient ◽  
One Pot Synthesis ◽  
The One

Abstract A highly efficient and stereoselective approach to the synthesis of biologically important and complex α-glycosyl phosphosaccharides (GPSs) has been disclosed, employing direct gold(I)-catalyzed glycosylation of the weakly nucleophilic phosphoric acid acceptors. The broad substrate scope is demonstrated with more than 45 examples, including glucose (Glc), xylose, glucouronatose, galactose (Gal), mannose (Man), rhamnose (Rha), fucose (Fuc), 2-N3-2-dexoxymannose (ManN3), 2-N3-2-dexoxyglucose (GlcN3), 2-N3-2-dexoxygalactose (GalN3) and unnatural carbohydrates. Moreover, the glycosyl phosphotriester prepared herein was successfully applied to the one-pot synthesis of a GPS from Leishmania donovani, and an effective preparation of a trisaccharide diphosphate of GPS fragments from Hansenula capsulate via iterative elongation strategy is realized.

A highly efficient approach to unnatural amino-acids containing 3-hydroxyoxindole skeleton via a one-pot, three-component procedure

2015 ◽  
Vol 56 (4) ◽  
pp. 586-589 ◽  
Author(s):  
Huang Huang ◽  
Yong Xu ◽  
Fei Mao ◽  
Jin Zhu ◽  
Hualiang Jiang ◽  
...  
Keyword(s):  
Amino Acids ◽  
Unnatural Amino Acids ◽  
One Pot ◽  
Efficient Approach ◽  
Highly Efficient ◽  
Component Procedure

Organocatalytic one-pot asymmetric synthesis of 2-aryl-2,3-dihydro-4-quinolones

RSC Advances ◽  
2016 ◽  
Vol 6 (30) ◽  
pp. 25375-25378 ◽  
Author(s):  
Gao-Fei Pan ◽  
Li Su ◽  
Yan-Lei Zhang ◽  
Shi-Huan Guo ◽  
Yong-Qiang Wang
Keyword(s):  
Asymmetric Synthesis ◽  
Enantioselective Synthesis ◽  
One Pot ◽  
Aryl Aldehydes ◽  
Highly Efficient

A highly efficient organocatalytic one-pot approach for enantioselective synthesis of (R)-2-aryl-2,3-dihydro-4-quinolones from o-aminoacetophenones and aryl aldehydes has been achieved.

One-pot, highly efficient, asymmetric synthesis of ring-fused piperidine derivatives bearing N,O- or N,N-acetal moieties

2016 ◽  
Vol 14 (8) ◽  
pp. 2444-2453 ◽  
Author(s):  
Ji-Yao Li ◽  
Zhi-Long Li ◽  
Wei-Wei Zhao ◽  
Yan-Kai Liu ◽  
Zhi-Ping Tong ◽  
...  
Keyword(s):  
Asymmetric Synthesis ◽  
Alder Reaction ◽  
Diels Alder ◽  
One Pot ◽  
Highly Efficient ◽  
Diels Alder Reaction

Lactols or cyclic hemiaminals are directly used as nucleophiles in the asymmetric aza-Diels–Alder reaction to synthesize ring-fused piperidine derivatives.

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