An efficient organic solvent-free methyltrioxorhenium-catalyzed epoxidation of alkenes with hydrogen peroxide

Methyltrioxorhenium (MTO) catalysis in the epoxidation of alkenes: a synthetic overview

Epoxides are biologically important moiety that is also used as synthetic intermediates. This review aims to present the up-to-date advancements in methyltrioxorhenium (MTO)-catalyzed epoxidation of alkenes using diverse oxidizing agents.

Catalytic Oxidation Processes for the Upgrading of Terpenes: State-of-the-Art and Future Trends

Terpenic olefins constitute a relevant platform of renewable molecules, which could be used as key intermediates for the perfumery, flavoring, and pharmaceutical industries. The upgrading of these cheap and available agro-resources through catalytic oxidation processes remains of great interest, leading to the formation of either epoxides via the oxidation of the olefinic bond or α,β-unsaturated ketones by the Csp3-H functionalization at the α-position of the double bond. This critical review summarizes some of the most relevant homogeneous or heterogeneous catalysts designed for the oxidation of some abundant terpenic olefins in the last decade (2008–2018).

Methyltrioxorhenium catalysis in nonconventional solvents: a great catalyst in a safe reaction medium

The requirement that chemical processes are sustainable, reflected in waste reduction and the use of safe reagents and reaction conditions, is becoming even more stringent as a result of pressure by society and governments to preserve the environment and protect human health. Catalysis offers numerous benefits related to green chemistry, including lowered energetic reaction requirements; catalytic, rather than stoichiometric, amounts of materials; increased selectivity; lowered consumption of processing and separation agents; and, in many cases, the use of less-toxic compounds. Our research group has for a long time been studying methyltrioxorhenium in the oxyfunctionalization of different substrates, by using H(2)O(2) or its urea-hydrogen peroxide complex as the primary oxidant. In this Review paper we aim to provide a full literature account on the catalytic activity and selectivity of methyltrioxorhenium in the oxyfunctionalization reaction, either in nonconventional solvents or under solvent-free conditions, with a particular emphasis on the use of ionic liquids as green reaction media.

13c-(2-Chloro-ethoxy)-1,13c-dihydro-2,3-epoxy-dibenzo[a,kl]xanthan-1-one

The title compound, C(22)H(15)ClO(4), containing three chiral C atoms, is an inter-mediate in the design of chiral alcohols. In the crystal structure, a chain structure is generated through C-H⋯O contacts and an intramolecular C-H⋯O interaction also occurs. The dihedral angle between the benzene ring and the naphthalene system is 16.5°.