A Practical and Regioselective Strategy for Aromatic C-H Difunctionalization via Site-Selective C-H Thianthrenation.

Herein, we present a novel Catellani-type reaction that employed aryl-thianthrenium salts as aryl substrates to trigger the subsequent palladium/norbornene cooperatively catalyzed progress. This strategy can achieve site-selective C-H difunctionalization of aryl compounds without directing groups or a known initiating reagent. A series of functionalized syntheses of bioactive molecules further demonstrated the potential of this strategy.

C-H Hydroxyalkylation or Methylation of Aryl Iodides by Ethers and TMSI via a Catellani Strategy.

In this paper, in the presence of trimethylsilyl iodide, the direct -C-H hydroxyalkylation/methylation of aryl iodines was effectively realized via palladium/norbornene cooperative catalysis when low-cost tetrahydrofuran and 1,2-dimethoxyethane were used as alkyl sources. Heck, Suzuki, and Sonogashira coupling and hydrogenation were all compatible with the reaction as termination steps. In addition, neuromuscular agents and cardiovascular agents were synthesized in one step by this method, showing their potential application value.

Copper-Catalyzed Hydrogen Atom Transfer and Aryl Migration Strategy for the Arylalkylation of Activated Alkenes.

Herein, we describe the copper-catalyzed arylalkylation of activated alkenes via hydrogen-atom transfer and aryl migration strategy. The reaction was carried out through a radical-mediated continuous migration pathway using -fluorosulfonamides as the alkyl source. The primary, secondary, and tertiary alkyl radicals formed by intramolecular hydrogen-atom transfer proceeded smoothly.

Site-selective coupling of remote C(sp)-H/-C(sp)-H bonds enabled by Ru/photoredox dual catalysis and mechanistic studies.

Construction of C(sp)-C(sp) bonds regioselective coupling of C(sp)-H/C(sp)-H bonds is challenging due to the low reactivity and regioselectivity of C-H bonds. Here, a novel photoinduced Ru/photocatalyst-cocatalyzed regioselective cross-dehydrogenative coupling of dual remote C-H bonds, including inert γ-C(sp)-H bonds in amides and -C(sp)-H bonds in arenes, to construct -alkylated arenes has been accomplished. This metallaphotoredox-enabled site-selective coupling between remote inert C(sp)-H bonds and -C(sp)-H bonds is characterized by its unique site-selectivity, redox-neutral conditions, broad substrate scope and wide use of late-stage functionalization of bioactive molecules.

Three-Component Ru-Catalyzed Regioselective Alkylarylation of Vinylarenes via -Selective C(sp)-H Bond Functionalization.

We report a novel Ru-catalyzed regioselective alkylarylation of vinylarenes with alkyl halides and arenes via -C(sp)-H bond functionalization to construct 1,1-diarylalkanes that generally show bioactivity. In this transformation, a wide spectrum of primary, secondary, and tertiary alkyl halides and electronically varied arenes was well-tolerated. This reaction is characterized by its exquisite regioselectivity of vinylarenes, unique -C(sp)-H selectivity, and redox-neutral conditions.

Lewis-Acid-Catalyzed Tandem Cyclization by Ring Expansion of Tertiary Cycloalkanols with Propargyl Alcohols.

A new method for the efficient synthesis of hexahydro-1-fluorene and octahydrobenzo[]azulene derivatives through a ring-expansion strategy is reported. With an appropriate combination of thulium(III) trifluoromethanesulfonate and 13X molecular sieves, a range of unsaturated polycyclic compounds were obtained in good yields. Mechanism studies reveal that the reaction is more likely to undergo Meyer-Schuster rearrangement, ring expansion, and Friedel-Crafts-type pathways, which provide a conceptually different strategy for the ring opening of tertiary cycloalkanols.

Copper-Catalyzed Direct Allenylation of Inactive Cyclic Ethers.

We report here a direct allenylation reaction of inactive cyclic ethers. The reaction proceeds through a copper-catalyzed 1,4-difunctionalization of 1,3-enynes, with cyano group installed at the allenes simultaneously. This methodology shows a broad functional group compatibility to 1,3-enynes.

Highly regioselective and stereoselective synthesis of C-Aryl glycosides nickel-catalyzed -C-H glycosylation of 8-aminoquinoline benzamides.

C-Aryl glycosides are of high value as drug candidates. Here a novel and cost-effective nickel catalyzed ortho-CAr-H glycosylation reaction with high regioselectivity and excellent α-selectivity is described. This method shows great functional group compatibility with various glycosides, showing its synthetic potential.

Cu-Catalyzed Direct C-H Alkylation of Polyfluoroarenes via Remote C(sp)-H Functionalization in Carboxamides.

A novel dehydrogenative coupling reaction of -fluorocarboxamides with polyfluoroarenes forming C(sp)-C(sp) bonds enabled by copper catalysis has been accomplished. -Fluorocarboxamides are postulated to undergo copper-mediated dehydrogenative cross-coupling reaction with electron-deficient polyfluoroarenes via a radical pathway. Benzylic C-H bonds and aliphatic C-H bonds in -fluorocarboxamides could proceed smoothly and demonstrated excellent regioselectivity.

Formation of -Allyl- and Allenyl-Modified Amides via Intermolecular Claisen Rearrangement.

We developed a new transition-metal-free intermolecular Claisen rearrangement process to introduce allyl and allenyl groups into the α position of tertiary amides. In this transformation, amides were activated by trifluoromethanesulfonic anhydride to produce the keteniminium ion intermediates that exhibit strong electrophilic activity. This atom-economical process delivers α position-modified amides under mild conditions in moderate to good yields and showcases a broad substrate compatibility.

Gold-Catalyzed Tandem Annulations of Pyridylhomopropargylic Alcohols with Propargyl Alcohols.

A gold-catalyzed tandem annulation of propargylic alcohols and pyridylhomopropargylic alcohols is achieved, providing an atom-economical approach to a diverse set of polycyclic dihydrobenzofurans in good yields. The reaction proceeds via the 5- cyclization/Meyer-Schuster rearrangement/Friedel-Crafts-type pathway. In this way, three C-C bonds and one C-O bond form to give a polycyclic skeleton in a one-pot process.

Three-component ruthenium-catalyzed remote C-H functionalization of 8-aminoquinoline amides.

Multicomponent reactions can efficiently construct complex molecular structures from simple precursors. Herein, a novel ruthenium-catalyzed three-component highly selective remote C-H functionalization of 8-aminoquinoline amides has been described. The reaction tolerates a wide range of functional groups, producing arylation/difluoroalkylation products of olefins with potential biological activity and pharmaceutical value.

Organocatalyzed Synthesis of Functionalized Quinolines.

As one of the most widely investigated compound skeleton, quinolines possess important medicinal and biological activities. As such, a great number of literatures, including reviews, have reported various methodologies to construct quinolines. Recently, organocatalyzed reactions have attracted the attention of organic chemists due to its being "green" because the reactions avoid the use of toxic metals.

New Friedel-Crafts strategy for preparing 3-acylindoles.

A selective Friedel-Crafts acylation of indoles via an unusual cleavage of the amide C-N bond was achieved by triflic anhydride activation. This method offers rapid efficient access to high-biological-value 3-acylindoles, performs a series of scrupulous mechanistic studies and offers a strong courage that amide synthons can form new C-C bonds under transition-metal-free conditions.

Transition-metal-free multinitrogenation of amides by C-C bond cleavage: a new approach to tetrazoles.

A metal-free brand-new one-pot multinitrogenation of amides for the chemo- and regioselective synthesis of 1,5-disubstituted tetrazoles has been developed. By means of electrophilic amide activation, and further C-C bond cleavage and rearrangement, a diverse set of functionalized 1,5-DST derivatives were selectively constructed under mild conditions. As showcased in the mechanisms, the chemoselectivity is easily switched by the selection of the starting materials in the reaction.

Wnt signaling pathway involvement in genotypic and phenotypic variations in Waardenburg syndrome type 2 with MITF mutations.

Mutation in the gene encoding microphthalmia-associated transcription factor (MITF) lead to Waardenburg syndrome 2 (WS2), an autosomal dominantly inherited syndrome with auditory-pigmentary abnormalities, which is clinically and genetically heterogeneous. Haploinsufficiency may be the underlying mechanism for WS2. However, the mechanisms explaining the genotypic and phenotypic variations in WS2 caused by MITF mutations are unclear.

Functional analysis of a SOX10 gene mutation associated with Waardenburg syndrome II.

Waardenburg syndrome (WS) is an autosomal dominant inherited non-syndromic type of hereditary hearing loss characterized by varying combinations of sensorineural hearing loss and abnormal pigmentation of the hair, skin, and inner ear. WS is classified into four subtypes (WS1-WS4) based on additional symptoms. WS2 is characterized by the absence of additional symptoms.

Synthesis of Functionalized Quinolines through a Reaction of Amides and Alkynes Promoted by Triflic Anhydride/Pyridine.

A concise, novel and flexible metal-free single step to synthesize functionalized quinolines is reported. Triflic anhydride-mediated (Tf O) activation of amides is discussed in the presence of pyridine to offer strong electrophiles, thereby showcasing excellent productivity, high regio- and chemoselectivity, and widely tolerable substrates. This approach provides a straightforward and efficient way to construct azaheterocycle structures.

The Value of Tumor Diameter in Predicting Prognosis of Nasopharyngeal Carcinoma Treated with Intensity-Modulated Radiotherapy.

Objective The tumor, node, and metastasis staging system of nasopharyngeal carcinoma (NPC) has limitations in predicting prognosis. The aim of this study was to explore the prognostic value of tumor diameter for patients with NPC who were treated with intensity-modulated radiotherapy. Study Design Case series with chart review.

Recommendations for Updating T and N Staging Systems for Nasopharyngeal Carcinoma in the Era of Intensity-Modulated Radiotherapy.

Objective: The aim of this study was to compare the 2008 Chinese and the 7th edition of the American Joint Committee on Cancer (AJCC) staging systems for nasopharyngeal carcinoma and to provide proposals for updating T and N staging systems of the present staging system.

Methods: Between January 2007 and December 2012, a cohort of 752 patients with biopsy-proven, newly diagnosed, non-metastatic nasopharyngeal carcinoma who were treated with intensity-modulated radiotherapy were retrospectively analysed. Prognoses were compared by T stage, N stage, and clinical stage according to the two staging systems for overall survival (OS), local relapse-free survival (LRFS), and distant metastasis-free survival (DMFS).

Transarterial chemoembolization compared with conservative treatment for advanced hepatocellular carcinoma with portal vein tumor thrombus: using a new classification.

We aimed to compare the survival benefit of transarterial chemoembolization (TACE) with conservative treatment for patients with advanced hepatocellular carcinoma (HCC) and portal vein tumor thrombus (PVTT), furthermore, to reveal which PVTT types benefit from TACE treatment. From August 2007 to January 2010, a prospective controlled study was performed on consecutive patients with advanced HCC and PVTT. Of a total of 150 patients, 115 were treated with TACE (lipiodol and anticancer agents ± gelatin sponge embolization), and 35 who refused to accept the procedure were treated with conservative treatment.