Type II intramolecular cycloadditions (4+2, 4+3, 4+4 and 5+2) have emerged recently as an efficient and powerful strategy for the construction of bridged ring systems. In general, type II ...cycloadditions provide access to a wide range of bridged bicyclo
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Type II intramolecular cycloadditions (4+2, 4+3, 4+4 and 5+2) have emerged recently as an efficient and powerful strategy for the construction of bridged ring systems.
A new metal‐free oxidative radical 2+2+1 carbocyclization of benzene‐linked 1,n‐enynes with two C(sp3)H bonds adjacent to the same heteroatom is described. This method achieves two C(sp3)H ...oxidative functionalizations and an annulation, thus providing efficient and general access to a variety of fused five‐membered carbocyclic hydrocarbons.
An oxidative functionalization of two C(sp3)H bonds adjacent to a same heteroatom for the 2+2+1 carbocyclization with benzene‐linked 1,n‐enynes is presented. This method successfully proceeds using a radical mechanism and provides straightforward access to a variety of fused five‐membered carbocyclic hydrocarbons. TBPB=tert‐butyl perbenzoate.
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An immobilized lipase with metal‐organic frameworks (MOFs) was first used for the kinetic resolution of mandelic acid enantiomers by transesterification reaction using vinyl acetate as acyl donor in ...organic medium. Notably, the biocompatibility of the carrier and catalytic performance of lipase could be significantly improved via modification of NH2‐Ni‐MOF with polyvinylpyrrolidone. After extensively screening the enzymatic process, the optimal enantioselective resolution conditions and excellent outcomes were obtained for the enzyme‐catalyzed transesterification reaction. In addition, the recovered immobilized lipase displayed outstanding reusability after immobilization.
Polyvinylpyrrolidone‐modified NH2‐Ni‐metal organic framework was used as carrier for immobilization of Pseudomonas fluorescens lipase. The immobilized lipase was applied to the resolution of mandelic acid enantiomers by kinetic transesterification with vinyl acetate in organic medium. The biocompatibility of the carrier, catalytic performance, and reusability of lipase could be significantly improved.
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Difunctionalization: Inexpensive and environmentally benign FeCl3 catalyzes the oxidative 1,2‐alkylarylation of activated alkenes with an aryl C(sp2)H bond and a C(sp3)H bond adjacent to a ...heteroatom. This reaction is a new strategy for the synthesis of oxindoles and makes use of DBU as ligand and TBHP as oxidant (see scheme, TBHP=tert‐butyl hydrogenperoxide).
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According to the very limited cancer registry, incidence and mortality rates for female breast cancer in China are regarded to be increasing especially in the metropolitan areas. Representative data ...on the breast cancer profile of Chinese women and its time trend over years are relatively rare. The aims of the current study are to illustrate the breast cancer profile of Chinese women in time span and to explore the current treatment approaches to female breast cancer.
This was a hospital-based nation-wide and multi-center retrospective study of female primary breast cancer cases. China was divided into 7 regions according to the geographic distribution; from each region, one tertiary hospital was selected. With the exception of January and February, one month was randomly selected to represent each year from year 1999 to 2008 at every hospital. All inpatient cases within the selected month were reviewed and related information was collected based on the designed case report form (CRF). The Cancer Hospital/Institute, Chinese Academy of Medical Sciences (CICAMS) was the leading hospital in this study.
Four-thousand two-hundred and eleven cases were randomly selected from the total pool of 45,200 patients and were included in the analysis. The mean age at diagnosis was 48.7 years (s.d. = 10.5 yrs) and breast cancer peaked in age group 40-49 yrs (38.6%). The most common subtype was infiltrating ductal carcinoma (86.5%). Clinical stage I & II accounted for 60.6% of 4,211 patients. Three-thousand five-hundred and thirty-four cases had estrogen receptor (ER) and progestin receptor (PR) tests, among them, 47.9% were positive for both. Two-thousand eight-hundred and forty-nine cases had human epidermal growth factor receptor 2(HER-2) tests, 25.8% of them were HER-2 positive. Among all treatment options, surgery (96.9% (4,078/4,211)) was predominant, followed by chemotherapy (81.4% (3,428/4,211). Much less patients underwent radiotherapy (22.6% (952/4,211)) and endocrine therapy (38.0% (1,599/4,211)).
The younger age of breast cancer onset among Chinese women and more advanced tumor stages pose a great challenge. Adjuvant therapy, especially radiotherapy and endocrine therapy are of great unmet needs.
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An oxidative sulfonylation/cyclisation of N‐propargylindoles with Hantzsch esters through sulfur dioxide insertion has been developed. The method uses Na2S2O5 as sulfur dioxide source along with ...4‐alkyl‐substituted Hantzsch esters as radical precursors for accessing sulfonyl radicals, and allows for the synthesis of 2‐sulfonated 9H‐pyrrolo1,2‐aindoles.
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A new photoinduced acylation/arylation of N‐(arylsulfonyl)acrylamide with acyl oxime esters through a nitrogen‐centered radical protocol has been disclosed for efficient preparation of functionalized ...indolin‐2‐ones, which proceeds through a cascade acyl radical addition of carbon‐carbon double bond, aryl migration, desulfonylation, and intramolecular cyclization sequence. This redox‐neutral strategy features excellent selectivity, good substituent tolerance, and wide substrate scope.
A new photoinduced acylation/arylation of N‐(arylsulfonyl)acrylamide with acyl oxime esters through a nitrogen‐centered radical protocol has been disclosed for efficient preparation of functionalized indolin‐2‐ones, which proceeds through a cascade acyl radical addition of carbon‐carbon double bond, aryl migration, desulfonylation, and intramolecular cyclization sequence. This redox‐neutral strategy features excellent selectivity, good substituent tolerance, and wide substrate scope.
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The oxidative interception of various σ‐alkyl palladium(II) intermediates with additional reagents for the difunctionalization of alkenes is an important research area. A new palladium‐catalyzed ...oxidative difunctionalization reaction of alkenes with α‐carbonyl alkyl bromides is described, in which the σ‐alkyl palladium(II) intermediate is generated through a Heck insertion and trapped using an aryl C(sp2)H bond. This method can be applied to various α‐carbonyl alkyl bromides, including primary, secondary, and tertiary α‐bromoalkyl esters, ketones, and amides.
Indolinone synthesis: A new palladium‐catalyzed oxidative difunctionalization reaction of N‐arylalkenes with primary, secondary, and tertiary α‐carbonyl alkyl bromides proceeds through a radical process and provides indolin‐2‐ones in moderate to excellent yields. The reaction is initiated by a Heck insertion followed by interception of the σ‐alkyl palladium(II) intermediate with aryl C(sp2)H bonds. dppe=1,2‐bis(diphenylphosphino)ethane.
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Background and Aims
The study objective was to compare the effectiveness of microwave ablation (MWA) and laparoscopic liver resection (LLR) on solitary 3–5‐cm HCC over time.
Approach and Results
From ...2008 to 2019, 1289 patients from 12 hospitals were enrolled in this retrospective study. Diagnosis of all lesions were based on histopathology. Propensity score matching was used to balance all baseline variables between the two groups in 2008–2019 (n = 335 in each group) and 2014–2019 (n = 257 in each group) cohorts, respectively. For cohort 2008–2019, during a median follow‐up of 35.8 months, there were no differences in overall survival (OS) between MWA and LLR (HR: 0.88, 95% CI 0.65–1.19, p = 0.420), and MWA was inferior to LLR regarding disease‐free survival (DFS) (HR 1.36, 95% CI 1.05–1.75, p = 0.017). For cohort 2014–2019, there was comparable OS (HR 0.85, 95% CI 0.56–1.30, p = 0.460) and approached statistical significance for DFS (HR 1.33, 95% CI 0.98–1.82, p = 0.071) between MWA and LLR. Subgroup analyses showed comparable OS in 3.1–4.0‐cm HCCs (HR 0.88, 95% CI 0.53–1.47, p = 0.630) and 4.1–5.0‐cm HCCs (HR 0.77, 95% CI 0.37–1.60, p = 0.483) between two modalities. For both cohorts, MWA shared comparable major complications (both p > 0.05), shorter hospitalization, and lower cost to LLR (all p < 0.001).
Conclusions
MWA might be a first‐line alternative to LLR for solitary 3–5‐cm HCC in selected patients with technical advances, especially for patients unsuitable for LLR.
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Covering: 2010 to 2020
Benzocycloheptane is a fundamental and unique structural motif found in pharmaceuticals and natural products. The total syntheses of natural products bearing the ...benzocycloheptane subunit are challenging and there are only a few efficient approaches to access benzocycloheptane. Thus, new methods and innovative strategies for preparing such natural products need to be developed. In this review, recent progress in the total syntheses of natural products bearing the benzocycloheptane motif is presented, and key transformations for the construction of benzocycloheptane are highlighted. This review provides a useful guide for those engaged in the syntheses of natural products containing the benzocycloheptane motif.
In this review, recent progresses in the total syntheses of natural products containing the benzocycloheptane motif are presented, and key transformations for the construction of benzocycloheptane are highlighted.
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