Allylic C–H Activations Using Cu(II) 2-Quinoxalinol Salen and <i>tert</i>-Butyl Hydroperoxide

Li, Yuancheng; Lee, Tae Bum; Wang, Tanyu; Gamble, Audrey V.; Gorden, Anne E. V.

doi:10.1021/jo300372q

Cited by 48 publications

(30 citation statements)

References 43 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Additionally, aldehyde (‐CHO) group can also be used for ligand conjugation on the MNP surfaces. Aldehyde group is well‐known to react with primary amine to form Schiff base . However, the formation of Schiff base is a reversible process.…”

Section: Targeted Delivery Of Theranostic Mnpsmentioning

confidence: 99%

Magnetic Nanoparticle Facilitated Drug Delivery for Cancer Therapy with Targeted and Image‐Guided Approaches

Huang

Orza

et al. 2016

Adv Funct Materials

Self Cite

238

146

View full text Add to dashboard Cite

With rapid advances in nanomedicine, magnetic nanoparticles (MNPs) have emerged as a promising theranostic tool in biomedical applications, including diagnostic imaging, drug delivery and novel therapeutics. Significant preclinical and clinical research has explored their functionalization, targeted delivery, controllable drug release and image-guided capabilities. To further develop MNPs for theranostic applications and clinical translation in the future, we attempt to provide an overview of the recent advances in the development and application of MNPs for drug delivery, specifically focusing on the topics concerning the importance of biomarker targeting for personalized therapy and the unique magnetic and contrast-enhancing properties of theranostic MNPs that enable image-guided delivery. The common strategies and considerations to produce theranostic MNPs and incorporate payload drugs into MNP carriers are described. The notable examples are presented to demonstrate the advantages of MNPs in specific targeting and delivering under image guidance. Furthermore, current understanding of delivery mechanisms and challenges to achieve efficient therapeutic efficacy or diagnostic capability using MNP-based nanomedicine are discussed.

show abstract

Section: Targeted Delivery Of Theranostic Mnpsmentioning

confidence: 99%

Magnetic Nanoparticle Facilitated Drug Delivery for Cancer Therapy with Targeted and Image‐Guided Approaches

Huang

Orza

et al. 2016

Adv Funct Materials

Self Cite

238

146

View full text Add to dashboard Cite

show abstract

“…[30b] Therefore, the peroxide was the major product for the oxidation under an inert atmosphere. The selectivity for 2‐cyclohexen‐1‐one ( B ) increases when the reaction is carried out under air (Table , entry 2) because the oxygen in the air can react with the cyclohexenyl radical to yield the ketone product Furthermore, 2‐cyclohexen‐1‐one is the major product for the reaction under an oxygen atmosphere (Table , entry 4) and overoxidation products, such as 2‐cyclohexene‐1,4‐dione and 7‐oxabicyclo[4.1.0] heptan‐2‐one, are observed as well. This result implies that, with excess oxygen, the rate of the reaction between the cyclohexenyl radical and oxygen is faster than that of the cyclohexenyl radical and the tert ‐butyl peroxide radical.…”

Section: Resultsmentioning

confidence: 99%

“…According to the reaction mechanism shown in Scheme , TBHP can be activated by the catalyst to generate active radicals. However, it is also known that TBHP can just decompose during the reaction . Therefore, the amount of TBHP is an important parameter to study.…”

Section: Resultsmentioning

confidence: 99%

“…The partial oxidation of alkenes has been widely studied with the challenge to selectively control the type of oxidation products. For example, the copper(II) 2‐quinoxalinol salen complex exhibits good activity in the homogeneous oxidation of cyclohexene with tert ‐butyl hydroperoxide (TBHP) to 2‐cyclohexen‐1‐one . Even though homogeneous catalysts generally provide good catalytic activity and selectivity, the difficulty in product separation and catalyst recyclability is an aspect inferior to that for heterogeneous catalysts.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Copper‐Functionalized Metal–Organic Framework as Catalyst for Oxidant‐Controlled Partial Oxidation of Cyclohexene

et al. 2018

View full text Add to dashboard Cite

Microwave irradiation is exploited for the facile, onestep functionalization of Cu(acac) 2 to -NH 2 pendant groups of MIL-53(Al)-NH 2 , a metal-organic framework material, under mild reaction conditions and a short reaction time. PXRD, XPS, XAS, and EPR spectroscopy are used to investigate the structure and chemical nature of the copper species on the framework. The copper center exists in the +2 oxidation state with a square-planar geometry and NO 3 coordination environment. The copper complex is anchored to the framework by imine bond formation. This copper-functionalized MIL-53(Al)-NH 2 or [a

show abstract

“…After screening reaction times, we found that three hours was optimal for completion of this reaction (entries 1-3). Among the various oxidants examined, TBPB was found to be more efficient for the explored reaction than other partners (entries [4][5][6][7][8][9][10][11][12][13]. It is noteworthy that the reaction did not occur in the presence of several types of peroxides and persulfides, such as cyclohexanone peroxide, benzoyl peroxide, ammonium persulfate, oxone, and potassium persulfate (entries 4-7 and 9).…”

mentioning

confidence: 99%

Approach to Trisubstituted 1H-Pyrroles from Alkynoates and Amines Mediated by tert-Butyl Perbenzoate

Liu¹,

Tan²,

Zhou³

et al. 2013

Synlett

View full text Add to dashboard Cite

A simple and concise tandem cyclization of alkynoates with amines in the presence of tert-butyl perbenzoate (TBPB) leads to 1,2,4-trisubstituted 1H-pyrroles. A variety of aromatic amines and aliphatic amines can be used in this approach, and a wide range of functionalized 1,2,4-trisubstituted 1H-pyrroles are obtained in good to excellent yields. This protocol not only corresponds to the construction of a pyrrole fragment, but also provides a new way to form C-C and C-N bonds.In the past decades, peroxides 1 have received much attention from chemists and drug design experts, which is reflected by the plethora of publications and reviews. [2][3][4][5][6][7][8] This class of compounds are widely used not only in academic research as oxidant, cross-linking agent, and polymerization initiator, but also in the production of cosmetics and pharmaceuticals as active components. 9-16 tert-Butyl perbenzoate (TBPB) is a typical example of an organic peroxide that contains more than 8.1% active oxygen. In this paper, we describe an expeditious synthetic approach to 1,2,4-trisubstituted 1H-pyrroles 17,18 through TBPB-promoted tandem cyclization of alkynoates and amines (Scheme 1). It is well-known that the pyrrole fragment 19,20 is an important synthon, due to the occurrence of this unit in many molecules that are of biological and pharmaceutical interest. [21][22][23][24] Initially, optimization of the reaction conditions was conducted; the results are summarized in Table 1. The model reaction of dimethyl but-2-ynedioate (1a) and p-toluidine (2a) in dioxane at 100°C occurred in the presence of tertbutyl peroxide (TBHP) and resulted in formation of the product dimethyl 1-p-tolyl-1H-pyrrole-2,4-dicarboxylate (3aa) in 57% GC yield (entry 1). After screening reaction times, we found that three hours was optimal for completion of this reaction (entries 1-3). Among the various oxidants examined, TBPB was found to be more efficient for the explored reaction than other partners (entries 4-13). It is noteworthy that the reaction did not occur in the presence of several types of peroxides and persulfides, such as cyclohexanone peroxide, benzoyl peroxide, ammonium persulfate, oxone, and potassium persulfate (entries 4-7 and 9). Results of the screening study of the amount of TBPB indicated that 2.3 equivalent of TBPB was sufficient for the reaction (entries 14-16). Finally, we investigated the effect of solvent for this protocol and found that dioxane was most suitable (entries 15 and 17-20).We then conducted a survey of the substrate scope of this protocol. The results, compiled in Table 2, demonstrate that a range of reactions could be performed with various alkynoates 1 and amines 2. It was observed that all the reactions were quite sensitive to the electronic contribution of the substituents on the benzene ring of the aromatic amines; amines such as 2a-g, with electron-donating groups on the benzene ring, all afforded the corresponding 1,2,4-trisubstituted 1H-pyrrole 3aa-ag in good to excellent isolated yields, whereas substrates wi...

show abstract

Allylic C–H Activations Using Cu(II) 2-Quinoxalinol Salen and tert-Butyl Hydroperoxide

Cited by 48 publications

References 43 publications

Magnetic Nanoparticle Facilitated Drug Delivery for Cancer Therapy with Targeted and Image‐Guided Approaches

Magnetic Nanoparticle Facilitated Drug Delivery for Cancer Therapy with Targeted and Image‐Guided Approaches

Copper‐Functionalized Metal–Organic Framework as Catalyst for Oxidant‐Controlled Partial Oxidation of Cyclohexene

Approach to Trisubstituted 1H-Pyrroles from Alkynoates and Amines Mediated by tert-Butyl Perbenzoate

Contact Info

Product

Resources

About