BackgroundCarcinoma ex pleomorphic adenoma (CXPA) is an uncommon malignant tumor with highly aggressive biological behavior. Our goal was to investigate the prognosis of CXPA in the major salivary glands and factors influencing it.MethodsWe retrospectively reviewed 51 patients diagnosed with CXPA of the major salivary glands between 1999 and 2006, comprising 36 males and 15 females, aged from 23 to 86 years. All patients underwent surgery with curative intention, and 21 received postoperative radiation therapy.ResultsOf the 51 patients, 39.2% developed locoregional recurrence and 27.5% developed distant metastases. Median follow-up was 54 months. At the time of analysis, 29 (56.9%) patients were deceased. Overall survival was 62.7% at 3 years and 50.3% at 5 years. Tumor-specific survival was 64.4% at 3 years and 53.5% at 5 years. Using chi-squared tests, invasiveness, T stage, lymph node involvement and clinical stage were found to be significantly associated with locoregional recurrence. Histological grade, invasiveness, lymph node involvement and perineural invasion were associated with distant metastases (P < 0.05). Cox analysis showed that T stage, lymph node involvement, histological grade and perineural invasion were independent prognostic factors for overall survival.ConclusionT stage, lymph node involvement, histological grade, perineural invasion and extent of invasion are important prognostic factors of CXPA in the major salivary glands. Surgery is the primary treatment modality for CXPA and postoperative radiation therapy may be used in patients with factors for poor prognosis.
An unprecedented organocatalytic asymmetric Michael/cyclization cascade reaction of 3-isothiocyanato oxindoles and 3-nitroindoles has been disclosed. A wide range of enantioenriched polycyclic spirooxindoles, containing three contiguous chiral centers with two of them having quaternary stereocenters, could be smoothly obtained with satisfactory results (up to 99% yield, >99:1 dr, and 96% ee). This method is very promising because the reaction is scalable, and the versatile transformations of the products into other spirocyclic oxindoles are also feasible. E xploring efficient strategies for the construction heterocyclic compounds with rich structural diversity and complexity is a continuing challenge in synthetic chemistry. The spirooxindole skeletons in particular have captured tremendous attention among synthetic and medicinal chemists, due to their prevalence in a broad range of natural and unnatural biologically active products, as well as pharmaceutically important compounds. 1 Over the past several years, we have witnessed rapid progress in the development of creative methodologies for the generation of diverse spirooxindole molecules. 2 Specifically, numerous multifunctional polycyclic spirooxindoles, featuring structural complexity and well-defined three-dimensional architecture, have been demonstrated to correlate with a wide spectrum of biological properties and pharmacological activities (Figure 1). 3 Various synthetic methods for producing functionalized spirooxindole derivatives containing a polycyclic skeleton in asymmetric catalysis have been reported. 4 Despite the substantial advances made thus far, taking into account the importance of the natural-product-like spirocyclic oxindoles in pharmaceutical science and as promising candidates for drug discovery, the development of novel approaches for the efficient synthesis of polyfunctionalized spirooxindoles is in demand.Since we initially employed 3-isothiocyanato oxindoles as nucleophiles in catalytic asymmetric synthesis, 5 many studies have documented the stereoselective construction of structurally diverse spirocyclic oxindoles using 3-isothiocyanato oxindoles as powerful and versatile precursors via cascade reaction. 6,7 Notably, 3-isothiocyanato oxindoles can easily undergo Michael/cyclization cascade reactions with some electrondeficient alkenes. 6 In addition, the indoles, bearing two electron-withdrawing substitutions at the N1-and C3-positon, have been recognized as a class of electron-deficient alkene reagents. 8 These indoles possess special reaction features; that is, they are readily attacked by nucleophiles at the C2-position and sequentially react with electrophiles at the C3-position (Scheme 1A). We noticed that 3-nitroindoles, 8 a class of potentially promising electrophilic alkenes, had barely been explored in the field of catalytic asymmetric synthesis. 9 In this context, as our continuous interest in developing new synthetic methods for the
The
first organocatalyzed asymmetric dearomative cycloaddition
between 2-nitrobenzofurans and isatin-derived Morita–Baylis–Hillman
carbonates has been developed. Using a modified cinchona alkaloid
as the catalyst, a series of structurally diverse cyclopenta[b]benzofuran derivatives with three contiguous stereocenters,
including a spiro-quaternary chiral center, could be smoothly obtained
in excellent results (all cases >20:1 dr, up to 99% yield and 98%
ee). The utility of this method was showcased by the versatile transformations
of the product.
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