Iron-Catalyzed Direct Julia-Type Olefination of Alcohols

Abstract

Herein, we report an iron-catalyzed, convenient, and expedient strategy for the synthesis of styrene and naphthalene derivatives with the liberation of dihydrogen. The use of a catalyst derived from an earth-abundant metal provides a sustainable strategy to olefins. This method exhibits wide substrate scope (primary and secondary alcohols) functional group tolerance (amino, nitro, halo, alkoxy, thiomethoxy, and S- and N-heterocyclic compounds) that can be scaled up. The unprecedented synthesis of 1-methyl naphthalenes proceeds via tandem methenylation/double dehydrogenation. Mechanistic study shows that the cleavage of the C–H bond of alcohol is the rate-determining step.

Cucurbit[6]uril-Supported Fe3O4 Magnetic Nanoparticles Catalyzed Green and Sustainable Synthesis of 2-Substituted Benzimidazoles via Acceptorless Dehydrogenative Coupling

“…It is one of the cheapest metals when compared to other precious metals. Besides being cost-effective, it is an eco-friendly and biologically compatible transition metal, which shows variable oxidation and spin states. , These properties of iron makes it a metal of choice for developing a cheap and eco-friendly catalyst for organic synthesis. − In this regard, Fe 3 O 4 magnetic nanoparticles (MNPs) have evolved as an efficient heterogeneous catalyst for a number of organic transformations. − Fe 3 O 4 MNPs have a cubic inverse spinel structure, where Fe is present in Fe 2+ and Fe 3+ cationic states. Fe 3 O 4 forms a cubic close-packed structure along the [110] direction by virtue of its unique magnetic structure .…”

Beyond classical sulfone chemistry: metal- and photocatalytic approaches for C–S bond functionalization of sulfones

“…More recently, Balaraman, Gupta and co-workers have broadened the catalytic arsenal for the olefination of benzylic alcohols employing a more sustainable metal complexes based on a Fe salt. 172 The strategy follows the aforementioned features for other acceptorless dehydrogenative coupling sequences developed so far for this transformation, in which the use of FeCl 2 in combination with the readily available 1,10-phenantroline as catalytic system delivered the desired olefin in medium to good yields (Scheme 87a). Both primary and secondary alcohols were found to react under this reaction conditions, in which the 1,1-diaryl alkene product was the major regioisomer when using secondary alcohols.…”

First‐Row Transition‐Metal Catalyzed Acceptorless Dehydrogenation and Related Reactions: A Personal Account

“…Our research group's direct olefination reaction was further extended using secondary alcohol under iron-based catalysis (Scheme 16). [31] Iron is one of the most abundant transition metals on the earth's crust and less toxic and inexpensive. Thus, cheap and efficient catalyst systems such as iron would be highly desirable in sustainable chemistry.…”