[3+2] Cycloaddition of Propargylamines and α‐Acylketene Dithioacetals: A Synthetic Strategy for Highly Substituted Pyrroles

Zhao, Yu‐Long; Di, Chong-Hui; Liu, Si‐Di; Meng, Jia; Liu, Qun

doi:10.1002/adsc.201200375

Cited by 28 publications

(13 citation statements)

References 55 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The authors reacted a series of N-propargylamines 466 with α-acylketene dithioacetals 467 in DMF, and pyrroles 468 were obtained in high-excellent yields (Scheme 100). 288 The proposed mechanism of the reaction involves a 1,4-Michael addition between 466 and 467 leading first to the intermediate 469, which is in equilibrium with 470. In the presence of a base, the imine 470 undergoes intramolecular 5exo-dig cyclization affording the intermediate 471 which is converted into the desired pyrroles 468 via a deacetylation and aromatization sequence.…”

Section: Miscellaneous Metal-free Synthesis Of Pyrrolesmentioning

confidence: 99%

Synthesis and Reactivity of Propargylamines in Organic Chemistry

et al. 2017

View full text Add to dashboard Cite

Propargylamines are a versatile class of compounds which find broad application in many fields of chemistry. This review aims to describe the different strategies developed so far for the synthesis of propargylamines and their derivatives as well as to highlight their reactivity and use as building blocks in the synthesis of chemically relevant organic compounds. In the first part of the review, the different synthetic approaches to synthesize propargylamines, such as A couplings and C-H functionalization of alkynes, have been described and organized on the basis of the catalysts employed in the syntheses. Both racemic and enantioselective approaches have been reported. In the second part, an overview of the transformations of propargylamines into heterocyclic compounds such as pyrroles, pyridines, thiazoles, and oxazoles, as well as other relevant organic derivatives, is presented.

show abstract

Section: Miscellaneous Metal-free Synthesis Of Pyrrolesmentioning

confidence: 99%

Synthesis and Reactivity of Propargylamines in Organic Chemistry

et al. 2017

View full text Add to dashboard Cite

show abstract

“…In our recent research, we found that reaction of 86a with commercially available propargylamine in DMF in the absence of an external base can afford 88a in good yield (Scheme ). In the presence of DBU (1,8-diazabicyclo[5.4.0]undec-7-ene) as the external base, both 88a and 89a were obtained.…”

Section: Heteroannulation Reactions Via Ketene Ns-acetalsmentioning

confidence: 99%

Chemistry of Ketene N,S-Acetals: An Overview

et al. 2016

Self Cite

View full text Add to dashboard Cite

Push-pull alkenes, which bear electron-donating and -accepting group(s) at both termini of a C═C double bond, respectively, are of interest not only for their unique electronic properties but also for their importance as versatile building blocks in organic synthesis. In the world of ketene acetals having the push-pull alkene skeleton, ketene N,S-acetal is most likely the biggest family according to the number and types of these compounds. The first ketene N,S-acetal compound was reported in 1956. As a cyclic ketene N,S-acetal compound, nithiazine, the first lead structure of neonicotinoid insecticides, was reported in 1978. The characteristics of ketene N,S-acetals, which have the structural feature of ketene S,S-acetals and enaminones, make them versatile and easy to use, especially in cyclization and multicomponent reactions for the synthesis of various heterocyclic systems and related natural products. There has been an increasing wealth of information about the synthesis and synthetic applications of ketene N,S-acetals, especially, in recent years. This review provides comprehensive knowledge on the chemistry of ketene N,S-acetals.

show abstract

“…It is noted that when external N-propargylamines (R 1 ¼ H) were used as substrates, the reaction was performed in the absence of an external base and the corresponding products were obtained in high to excellent yields. 7 Recently, Jin and co-workers demonstrated that polysubstituted pyrroles 16 can be readily prepared in the reaction of N-propargylamines 14 with activated alkynes 15 in the presence of 20 mol% of K 3 PO 4 as catalyst in DMSO at 120 C (Scheme 6) The authors suggested that the reaction proceeds via the formation of N-propargylic b-enaminoester intermediates A through Michael addition of N-propargylamines 14 to alkynes 15, which aer a 5-exo-dig cyclization process delivers the 3carboxylated pyrroles 16 in good yields. 8 Later, Zhang's research team reported a direct synthesis of polysubstituted pyrrole derivatives 18 via base-catalyzed intramolecular cyclization of N-propargylic b-enaminones 17 (Scheme 7).…”

Section: Pyrrolesmentioning

confidence: 99%