Microwave-Assisted [3 + 2] Cycloadditions of Azomethine Ylides

Bashiardes, George; Safir, Imad; Mohamed, Achmet Said; Barbot, F.; Laduranty, J.

doi:10.1021/ol0361195

Cited by 50 publications

(23 citation statements)

References 8 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…[18,1920] Imines 8 (R 1 = Ph) do not react under thermal conditions, so the use of the more reactive iminium cations type 10 is recommended in this case. [21,22,23,24,25,26] [a] Laboratório de Química Biorgânica, Núcleo Considering both strategies, there are two difficulties to overcome. In the first route, the resulting imine 8 is, in some cases, unstable, and in the second one, N-alkyl amino esters 9 have to be prepared.…”

Section: Introductionmentioning

confidence: 99%

Synthesis of Chromen[4,3‐b]pyrrolidines by Intramolecular 1,3‐Dipolar Cycloadditions of Azomethine Ylides: An Experimental and Computational Assessment of the Origin of Stereocontrol

et al. 2015

View full text Add to dashboard Cite

Azomethine ylides, generated from imines derived Ocynnamyl or O-crotonyl salicylaldeyde and α-amino acids, undergo intramolecular 1,3-dipolar cycloaddition, leading to chromene-[4,3-b]-pyrrolidines. Two reaction conditions are used: a) microwave irradiation (200W) assisted heating (185 ºC) of a neat mixture of reagents, and b) conventional heating (170 ºC) in PEG-400 as solvent. In both cases mixture of two epimers at the α-position of the nitrogenatom in the pyrrolidine nucleus was formed through the less energetic endo-approach (B/C ring fusion). In many cases, the formation of the stereoisomer bearing a transarrangement into the B/C ring fusion in high proportions. A comprehensive computational and kinetic simulation studies are detailed. The analysis of the stability of transient 1,3-dipoles, followed by the assessment of intramolecular pathways and kinetic are carefully performed.

show abstract

Section: Introductionmentioning

confidence: 99%

Synthesis of Chromen[4,3‐b]pyrrolidines by Intramolecular 1,3‐Dipolar Cycloadditions of Azomethine Ylides: An Experimental and Computational Assessment of the Origin of Stereocontrol

et al. 2015

View full text Add to dashboard Cite

show abstract

“…Except for the entry 7, the major products presented fusion cis between the benzopiranic (B) and pirrolidinic (C) rings. 2 The major products in each reaction could be enriched after column chromatography. The structure of the major product of entry 1 was confirmed by X-ray of N-tosylated derivative 3 (Scheme 2).…”

Section: Resultsmentioning

confidence: 99%

Synthesis of Aza-Pterocarpan Analogues via 1,3 Intramolecular Dipolar Cycloadditions in in situ generated Iminoolefins

Barcellos¹,

Dias²,

Sansano³

et al. 2013

Proceedings of the 15th Brazilian Meeting on Organic Synthesis Proceedings

View full text Add to dashboard Cite

“…48 To a solution of K 2 CO 3 (1.5 mmol) and salicylaldehyde (0.5 mmol) in 3 mL of dry DMF, (R)-4-phenylbut-3-yn-2-yl methanesulfonate 3a in DMF (2 mL) was added dropwise. The reaction mixture was stirred at room temperature for 6 h and subsequently cooled to 0°C.…”

Section: General Methodsmentioning

confidence: 99%

Utilization of whole cell mediated deracemization in a chemoenzymatic synthesis of enantiomerically enriched polycyclic chromeno[4,3-b] pyrrolidines

Saravanan¹,

Jana²,

Chadha³

2014

Org. Biomol. Chem.

View full text Add to dashboard Cite

Various aryl and alkyl substituted optically pure propargyl alcohols were obtained with excellent ee (up to >99%) and isolated yields (up to 87%) by deracemization using whole cells of Candida parapsilosis ATCC 7330. The whole cells show substrate specificity towards alkyl substituted propargyl alcohols and a switch in the enantioselectivity has been observed from 'R' to 'S' upon increasing the chain length. For the first time, enantiopure (R)-4-(3-hydroxybut-1-ynyl)benzonitrile, (R)-4-(biphenyl-4-yl)but-3-yn-2-ol, (S)-ethyl 3-hydroxy-5-phenylpent-4-ynoate and (S)-4-phenylbut-3-yne-1,2-diol were obtained using this strategy. Optically pure propargyl alcohol thus obtained was used as a chiral starting material in the synthesis of enantiomerically enriched poly-substituted pyrrolidines and a pyrrole derivative successfully demonstrating a chemoenzymatic route.

show abstract

Microwave-Assisted [3 + 2] Cycloadditions of Azomethine Ylides

Cited by 50 publications

References 8 publications

Synthesis of Chromen[4,3‐b]pyrrolidines by Intramolecular 1,3‐Dipolar Cycloadditions of Azomethine Ylides: An Experimental and Computational Assessment of the Origin of Stereocontrol

Synthesis of Chromen[4,3‐b]pyrrolidines by Intramolecular 1,3‐Dipolar Cycloadditions of Azomethine Ylides: An Experimental and Computational Assessment of the Origin of Stereocontrol

Synthesis of Aza-Pterocarpan Analogues via 1,3 Intramolecular Dipolar Cycloadditions in in situ generated Iminoolefins

Utilization of whole cell mediated deracemization in a chemoenzymatic synthesis of enantiomerically enriched polycyclic chromeno[4,3-b] pyrrolidines

Contact Info

Product

Resources

About