Tandem Chloropalladation/Cyclization and Dearomative Cyclization toward Functionalized Tricyclic Bridged [3.2.1] Skeleton Compounds

Dong, Yunhui; Du, Nana; Li, Xueyuan; Zheng, Litao; Liu, Gang

doi:10.1021/acs.orglett.5b02076

Cited by 15 publications

(8 citation statements)

References 48 publications

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“…This reaction led to 8-or 6-carbonyl [3.2.1] skeletons in high levels of efficiency. 386 Jiang also reported an oxidiative amino bromination of electron-deficient alkenes using anilines and LiBr in 2013 (Scheme 222). 387 The authors conducted several control experiments in order to gain mechanistic insight for this transformation.…”

Section: Carbohalogenation Of Alkynes By Halometalationmentioning

confidence: 99%

Modern Transition-Metal-Catalyzed Carbon–Halogen Bond Formation

2016

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The high utility of halogenated organic compounds has prompted the development of a vast number of transformations which install the carbon-halogen motif. Traditional routes to these building blocks have commonly involved multiple steps, harsh reaction conditions, and the use of stoichiometric and/or toxic reagents. In this regard, using transition metals to catalyze the synthesis of organohalides has become a mature field in itself, and applying these technologies has allowed for a decrease in the production of waste, higher levels of regio- and stereoselectivity, and the ability to produce enantioenriched target compounds. Furthermore, transition metals offer the distinct advantage of possessing a diverse spectrum of mechanistic possibilities which translate to the capability to apply new substrate classes and afford novel and difficult-to-access structures. This Review provides comprehensive coverage of modern transition metal-catalyzed syntheses of organohalides via a diverse array of mechanisms. Attention is given to the seminal stoichiometric organometallic studies which led to the corresponding catalytic processes being realized. By breaking this field down into the synthesis of aryl, vinyl, and alkyl halides, it becomes clear which methods have surfaced as most favored for each individual class. In general, a pronounced shift toward the use of C-H bonds as key functional groups, in addition to methods which proceed by catalytic, radical-based mechanisms has occurred. Although always evolving, this field appears to be heading in the direction of using starting materials with a significantly lower degree of prefunctionalization in addition to less expensive and abundant metal catalysts.

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Section: Carbohalogenation Of Alkynes By Halometalationmentioning

confidence: 99%

Modern Transition-Metal-Catalyzed Carbon–Halogen Bond Formation

2016

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“…Under particular circumstances, an initial nucleophilic attack to the triple bond coordinated to Pd(II) by an external nucleophile may be followed by double cyclization. In a remarkable example, 5‐chloro‐2,3‐dihydro‐8 H ‐3,5a‐methanobenzo[ b ]oxepin‐8‐ones were synthesized in moderate to high yields starting from 1‐(3‐oxoprop‐1‐ynyl)‐2,4‐diallyloxybenzenes, with PdCl 2 (MeCN) 2 as the catalyst and CuCl 2 /O 2 as the reoxidizing system (Scheme ) . Initial chloride attack to coordinated triple bond led to a chlorovinylpalladium intermediate, which underwent intramolecular double bond insertion followed by intramolecular dearomative palladation at C‐5a, assisted by the allyloxy group at C‐8.…”

Section: Pd(ii)‐catalyzed Processesmentioning

confidence: 99%

“…Initial chloride attack to coordinated triple bond led to a chlorovinylpalladium intermediate, which underwent intramolecular double bond insertion followed by intramolecular dearomative palladation at C‐5a, assisted by the allyloxy group at C‐8. This gave a bridged palladacycle intermediate, from which the final product was obtained by reductive elimination followed by chloride‐induced deallylation (Scheme ) …”

Section: Pd(ii)‐catalyzed Processesmentioning

confidence: 99%

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Palladium‐Catalyzed Double Cyclization Processes Leading to Polycyclic Heterocycles: Recent Advances

et al. 2019

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In this minireview, we discuss some recently reported methods for the synthesis of polycyclic heterocycles by palladium‐catalyzed double cyclization processes. Paradigmatic examples taken by the most recent literature (from 2014 to the beginning of 2019) are presented. Only transformations in which palladium is involved in at least one cyclization stage are taken into consideration. The first part deals will Pd(0)‐catalyzed processes. Double cyclizations initiated by the oxidative addition of an Ar–X bond or other functional groups are treated first, followed by processes beginning with carbopalladation by Pd(0) attack to unsaturated bonds. The second part concerns Pd(II)‐catalyzed reactions, and begins with double cyclizations initiated by intramolecular nucleophilic attack to unsaturated bonds coordinated to Pd(II), followed by processes initiated by aromatic palladation.

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“…Polysulfide compound (PsC) exists in natural H 2 S donors, such as diallyl trisulfide and lanthionine, which produces H 2 S efficiently by thiol‐polysulfide cleavage mechanism. [ 16 ] Notably, the tumor microenvironment is more thiol‐abundant than healthy tissues, [ 17 ] which naturally endowed PsC the tumor‐specific H 2 S‐release. Therefore, we exploited polysulfide‐based nanoparticles as efficient H 2 S donors for specific H 2 S therapy on TNBC.…”

Section: Introductionmentioning

confidence: 99%

Efficient Polysulfide‐Based Nanotheranostics for Triple‐Negative Breast Cancer: Ratiometric Photoacoustics Monitored Tumor Microenvironment‐Initiated H₂S Therapy

Yuan

et al. 2020

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The incidence of triple‐negative breast cancer (TNBC) is difficult to predict, and TNBC has a high mortality rate among women worldwide. In this study, a theranostics approach is developed for TNBC with ratiometric photoacoustic monitored thiol‐initiated hydrogen sulfide (H2S) therapy. The ratiometric photoacoustic (PA) probe (CY) with a thiol‐initiated H2S donor (PSD) to form a nanosystem (CY‐PSD nanoparticles) is integrated. In this theranostics approach, H2S generated from PSD is sensed by CY based on ratiometric PA signals, which simultaneously pinpoints the tumor region. Additionally, H2S is cytotoxic toward TNBC cells (MDA‐MB 231), showing a tumor inhibition rate of 63%. To further verify its pharmacological mechanism, proteomics analysis is performed on tumors treated with CY‐PSD nanoparticles. Cells are killed by the significant mitochondrial dysfunction via supressed energy supply and apoptosis initiation. Besides, the observed inhibition of oxidative stress also generates the cytotoxicity. Significant Kyoto Encyclopedia of Genes Genomes pathways related to TNBC are found to be inhibited. This H2S theranostics approach updates the current anticancer therapies which brings promise for women suffering malignant breast cancer.

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Tandem Chloropalladation/Cyclization and Dearomative Cyclization toward Functionalized Tricyclic Bridged [3.2.1] Skeleton Compounds

Cited by 15 publications

References 48 publications

Modern Transition-Metal-Catalyzed Carbon–Halogen Bond Formation

Modern Transition-Metal-Catalyzed Carbon–Halogen Bond Formation

Palladium‐Catalyzed Double Cyclization Processes Leading to Polycyclic Heterocycles: Recent Advances

Efficient Polysulfide‐Based Nanotheranostics for Triple‐Negative Breast Cancer: Ratiometric Photoacoustics Monitored Tumor Microenvironment‐Initiated H₂S Therapy

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Tandem Chloropalladation/Cyclization and Dearomative Cyclization toward Functionalized Tricyclic Bridged [3.2.1] Skeleton Compounds

Cited by 15 publications

References 48 publications

Modern Transition-Metal-Catalyzed Carbon–Halogen Bond Formation

Modern Transition-Metal-Catalyzed Carbon–Halogen Bond Formation

Palladium‐Catalyzed Double Cyclization Processes Leading to Polycyclic Heterocycles: Recent Advances

Efficient Polysulfide‐Based Nanotheranostics for Triple‐Negative Breast Cancer: Ratiometric Photoacoustics Monitored Tumor Microenvironment‐Initiated H2S Therapy

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Efficient Polysulfide‐Based Nanotheranostics for Triple‐Negative Breast Cancer: Ratiometric Photoacoustics Monitored Tumor Microenvironment‐Initiated H₂S Therapy