A Role for Isatin Azomethine Imines as a Dipolarophile in Cycloaddition Reactions

Fang, Qing-Yun; Jin, Hai‐Shan; Wang, Rubing; Zhao, Li‐Ming

doi:10.1021/acs.orglett.0c02705

Cited by 20 publications

(10 citation statements)

References 46 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Aza-oxyallyl cations were reported to undergo an unusual [2 + 3] cycloaddition with isatin azomethine imines using Na 2 CO 3 in HFIP/DCM (Scheme ). Both HFIP and DCM promoted the transformation, with HFIP, providing slightly higher yields TFE did not provide any cycloadduct. The reaction yield was increased by using 1:1 HFIP/DCM, presumably due to the ability of DCM to better solubilize the azomethine imines.…”

Section: Pericyclic Reactionsmentioning

confidence: 99%

HFIP in Organic Synthesis

et al. 2022

View full text Add to dashboard Cite

1,1,1,3,3,3-Hexafluoroisopropanol (HFIP) is a polar, strongly hydrogen bond-donating solvent that has found numerous uses in organic synthesis due to its ability to stabilize ionic species, transfer protons, and engage in a range of other intermolecular interactions. The use of this solvent has exponentially increased in the past decade and has become a solvent of choice in some areas, such as C–H functionalization chemistry. In this review, following a brief history of HFIP in organic synthesis and an overview of its physical properties, literature examples of organic reactions using HFIP as a solvent or an additive are presented, emphasizing the effect of solvent of each reaction.

show abstract

Section: Pericyclic Reactionsmentioning

confidence: 99%

HFIP in Organic Synthesis

et al. 2022

View full text Add to dashboard Cite

show abstract

“…The free‐energy profiles shown in Figure 4 can explain why P1 is the sole product observed by Zhao's group [26] . Since TS ‐ 2’ is only 0.8 kcal/mol higher‐lying than INT ‐ 1 , imidate P2 should be the kinetically favored product.…”

Section: Resultsmentioning

confidence: 90%

“…In Zhao's experimental work, the use of a mixed solvent of HFIP and DCM gave moderately higher yields than the use of DCM solvent [26] . We have tentatively treated the explicit solvation effect on the mechanism and energetics by introducing several HFIP molecules to some important stationary points [30] .…”

Section: Resultsmentioning

confidence: 99%

“…In 2020, Zhao's group reported a [3+2] cycloaddition reaction between isatin azomethine imine ( R1 ) and α‐bromohydroxamate ( R2 ) to produce the 4‐oxazolidinone product ( P1 ) in high yield at room temperature (see Scheme 2). [26] Sodium carbonate was responsible for the generation of the active azaoxyallyl cation from R2 , and the mixed solvent of hexafluoro‐2‐propanol (HFIP) and DCM was proved to be the best choice. The cycloaddition exclusively occurred at the carbonyl group of R1 , and the [3+3] process between the azaoxyallyl cation and the azomethine imine moiety was not observed (i. e., P3 was not detected).…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

A Computational Study on Cycloaddition Reactions between Isatin Azomethine Imine and in situ Generated Azaoxyallyl Cation

2022

View full text Add to dashboard Cite

The cycloaddition reactions between isatin azomethine imine and in situ generated azaoxyallyl cation were explored by density functional theory calculations to elucidate the competition among different pathways. The [3+2] cycloaddition between azaoxyallyl cation and carbonyl group could proceed via either the N‐alkylated pathway or O‐alkylated pathway, which finally afforded the 4‐oxazolidinone or imidate skeleton, respectively. The exclusive formation of the 4‐oxazolidinone product should result from the higher stability and feasible conversion. The possibly competing [3+3] reaction between azaoxyallyl cation and azomethine imine was predicted to be less favorable kinetically than the [3+2] one. Lastly, charge and orbital analyses were performed on isatin azomethine imine to explain the observed reactivities.

show abstract

“…To show the practicality of the reaction desired product was obtained from N-methylisatin 38, 3-pyrazolidinone 39, and α-halohydroxamates in one pot synthesis (Scheme 11). [24] Cyclic λ 3 -iodanes, for example, ethynylbenziodoxolones (EBXs) is used as versatile electrophilic group transfer reagent. [25a-b] Due to synthetic applicability various modified EBXs have been synthesized.…”

Section: [3 + 2]-cycloaddition Reactionsmentioning

confidence: 99%

Aza‐oxyallyl Cations and Their Applications in (3+m) Cycloaddition Reactions

Deeksha

Singh

2022

Eur J Org Chem

View full text Add to dashboard Cite

Aza‐oxyallyl cations, as proposed by Sheehan in the 1960s have garnered significant attention among the synthetic organic community, owing to their diverse reactivity profile for constructing N‐scaffolds of biological interest. During its initial growth, aza‐oxyallyl cations were used effectively as a 3‐unit synthon as 1,3 dipoles to create N‐heterocycles via cycloaddition reactions, wherein aza‐oxyallyl cation served as electrophilic counterpart. Recently, new variations of aza‐oxyallyl cations reactivity have been reported, including its usage as a 1,4 dipole in cycloaddition reactions, domino reactions, and the unique alkylating ability of heteroatoms. This review article provides an update of the recent developments in this area and the prevailing mechanistic insight.

show abstract

A Role for Isatin Azomethine Imines as a Dipolarophile in Cycloaddition Reactions

Cited by 20 publications

References 46 publications

HFIP in Organic Synthesis

HFIP in Organic Synthesis

A Computational Study on Cycloaddition Reactions between Isatin Azomethine Imine and in situ Generated Azaoxyallyl Cation

Aza‐oxyallyl Cations and Their Applications in (3+m) Cycloaddition Reactions

Contact Info

Product

Resources

About