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Methyltrioxorhenium and perrhennate salts catalyze the deoxydehydration (DODH) of glycols by sulfite, producing olefins regiospecifically. The scope and efficiency of these reactions with respect to the polyol substrate, reducing agent, catalyst, solvents, and various additives are investigated. In general, MeReO3 is a more active catalyst for sulfite-driven DODH, but the Z+ReO4 – derivatives (Z = Na, Bu4N) are more selective. Epoxides are also deoxygenated by Na2SO3/MeReO3, but not by Bu4NReO4. The perrhenate catalysts also promote glycol DODH with other reductants, e.g., PR3, secondary alcohols, and ArSMe. The DODH reactions of 1,2-cyclohexanediol and (+)-diethyl tartrate occur with high syn-stereoselectivity. The polyol meso-erythritol is largely converted to 1,3-butadiene with minor amounts of 2-butene-1,4-diol and 2,5-dihydrofuran, indicating faster terminal glycol DODH. Stoichiometric reaction studies demonstrate the viability of a catalytic pathway involving (a) glycol condensation with MeReO3 to form MeReVIIO2(glycolate); (b) O-transfer reduction of the ReVII-glycolate by sulfite or PR3 to produce [MeRevO(glycolate)]2; and (c) thermal fragmentation of the reduced Re-glycolates to produce olefin (and regeneration of MeReO3).

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AimMacrodystrophia lipomatosa is a rare cause of gigantism of limb which can be confused with other common causes like congenital lymphedema. It presents usually with loss of function and cosmetic problems. Four cases are described with emphasis on clinical presentation, differential diagnoses, imaging and treatment options.Methods & ResultsFour patients of macrodystrophia lipomatosa were thoroughly examined and subjected to investigations.ConclusionBesides diligent clinical examination, imaging and histopathology are crucial in clinching the diagnosis.

Cancer is one of the major causes of worldwide human mortality. A wide range of cytotoxic drugs are available on the market, and several compounds are in different phases of clinical trials. Many studies suggest that these cytotoxic molecules are also associated with different types of adverse side effects; therefore researchers around the globe are involved in the development of more efficient and safer anticancer drugs. In recent years, quinazoline and its derivatives have been considered as a novel class of cancer chemotherapeutic agents that show promising activity against different tumors. The aim of this article is to comprehensively review and highlight the recent developments concerning the anticancer activity of quinazoline derivatives as well as offer perspectives on the development of novel quinazoline derivatives as anticancer agents in the near future.