Iodolactonization of 3-Alkynylthiophene-2-Carboxylic and 3-Alkynylpicolinic Acids for the Synthesis of Fused Heterocycles

The iodolactonization of 3-alkynylthiophene-2-carboxylic acids and 3-alkynylpicolinic acids has been investigated. Using I2 as the iodine source and NaHCO3 as the base in MeCN, the process took place smoothly to afford thienopyranones and pyranopyridinones, respectively, from 6-endo-dig cyclization. The method also worked nicely for the transformation of 2-(phenylethynyl)thiophene-3-carboxylic acid and 3-(phenylethynyl) isonicotinic acid into 7-iodo-6-phenyl-4H-thieno[3,2-c]- pyran-4-one and 4-iodo-3-phenyl-1H-pyrano[4,3-c]pyridin-1- one, respectively. Although with some 3-alkynylpicolinic acids the process led to a mixture of the 6-endo-dig and 5-exo-dig products, it could be still made selective toward the pyranopyridinone compound working in 1-ethyl-3-methylimidazolium ethyl sulfate as the solvent. On the other hand, the exclusive formation of the 5-exo-dig product was observed in N-ethyl-Nmethylmorpholinium dicyanamide starting from 3-(3,3-dimethylbut- 1-yn-1-yl)picolinic acid. Some representative iodinated thienopyridinone products were successfully used as substrates for Pd-catalyzed Suzuki and Sonogashira reactions

Unusual presentation of intravascular papillary endothelial hyperplasia (Masson's tumor)

Intravascular papillary endothelial hyperplasia is a rare, exuberant form of reactive endothelial proliferation which can mimic benign and malignant vascular tumors. In this report, we describe a 22-year-old man presenting with a 2.5 cm nodule on his left foot, near the first metatarsal head. The patient underwent total excision of the lesion, with subsequent histological diagnosis of intravascular papillary endothelial hyperplasia arising within a thrombosed periosteal vein. After nine months from surgery, the patient is alive and well, with no evidence of local recurrence

Hormonal therapy for fertility and huge meningioma: a purely random association?

Sexual hormones have been related to the growth of meningiomas, also due to the almost constant expression of hormonal receptors by tumoral cells. A case of a woman with previous history of multiple treatment for infertility, harboring a huge meningioma is here described. The tumor was surgically resected and the immunohistochemical examination revealed a high expression of progesterone receptors on tumoral cells surface. A putative role of past progesterone administration in the growth of meningioma has been hypothesized. Particular caution should be paid whenever adopting sexual hormonal therapy, especially for fertility. A radiological examination (ideally MRI) could be advised before starting therapy, in order to rule out any intracranial meningioma

(S)-4-Isopropyl-5,5-diphenyloxazolidin-2-one

(S)-4-Isopropyl-5,5-diphenyloxazolidin-2-one has been synthesized for the first time by the enantiospecific oxidative carbonylation of commercially available (S)-2-amino-3-methyl-1,1-diphenylbutan-1-ol. The cyclocarbonylation reaction was carried out at 100 °C in 1,2-dimethoxyethane (DME) as the solvent for 15 h, under 20 atm of a 4:1 mixture of CO–air and in the presence of the catalytic system PdI2/KI (substrate:KI:PdI2 molar ratio = 100:10:1), to give the oxazolidinone derivative in 81% isolated yield

Is CRX protein a useful marker in differential diagnosis of tumors of the pineal region?

The cone-rod homeobox (CRX) is a gene that belongs to the member of the orthodenticle homeobox (Otx) family, with important function in development and differentiation of retinal and pineal cells. Moreover, CRX appears to be specifically expressed in pineal tumors and retinoblastomas. We performed an immunohistochemical study on 91 pediatric and adult central nervous system tumors, plus 2 normal brain samples. Our results demonstrated that CRX is expressed not only in pineal parenchymal tumors and retinoblastoma, but also in a some medulloblastomas and supratentorial primitive neuroectodermal tumors. None of the glial tumors screened were positive for CRX. In conclusion, CRX could be useful in surgical neuropathology for the differential diagnosis of pineal region tumors, in particular to discriminate pineal tumors from glial tumors

A cortical cystic epileptogenic lesion: Tanycytic ependymoma

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(S)-4-Isopropyl-5,5-diphenyloxazolidin-2-one

(S)-4-Isopropyl-5,5-diphenyloxazolidin-2-one has been synthesized for the first time by the enantiospecific oxidative carbonylation of commercially available (S)-2-amino-3-methyl-1,1-diphenylbutan-1-ol. The cyclocarbonylation reaction was carried out at 100 °C in 1,2-dimethoxyethane (DME) as the solvent for 15 h, under 20 atm of a 4:1 mixture of CO–air and in the presence of the catalytic system PdI2/KI (substrate:KI:PdI2 molar ratio = 100:10:1), to give the oxazolidinone derivative in 81% isolated yield

The fate of a macroporous hydroxyapatite cranioplasty four years after implantation: macroscopical and microscopical findings in a case of recurrent atypical meningioma

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A palladium iodide catalyzed regioselective carbonylative route to isocoumarin and thienopyranone carboxylic esters

The reactivity of 2-alkynylbenzoic acids under PdI2/KI-catalyzed oxidative alkoxycarbonylation conditions, with oxygen (from air) as external oxidant and an alcohol as external nucleophile, has been studied. It was found that substrates with triple bond substituted with a bulky alkyl group, such as tert-butyl, selectively underwent a 6-endo-dig cyclization - alkoxycarbonylation pathway with ethanol or isopropanol as nucleophile, to give high value added isocoumarin-4-carboxylic esters in good to high yields (67–87%). When applied to alkynylthiophencarboxylic acids bearing an internal triple bond, the reaction turned out to be completely regioselective toward the formation of the corresponding alkyl thienopyranonecarboxylates ensuing from 6-endo-dig cyclization-alkoxycarbonylation, regardless the nature of the substituent on the triple bond and the external alcohol (54–91% yields). To confirm the structure of the products deriving from different kinds of substrates, and therefore to corroborate the proposed mechanistic pathways, the crystalline structures of 11 new compounds have been resolved by XRD analysis