Iron‐Catalyzed Dioxygenation of Alkenes and Terminal Alkynes by using (Diacetoxyiodo)benzene as Oxidant

Abstract

An iron-catalyzed syn-diacetoxylation of alkenes and 1,2-oxyacetoxylation of terminala lkynes has been developed using (diacetoxyiodo)benzenea s oxidant. Ab road range of internal and terminal alkenes, including electron-rich as wella se lectron-deficient alkenes,g avet he desired products in good to excellent yields with high diastereoselectivity (up to > 99:1 dr). In addition the high catalytic activity of iron catalysisfor the 1,2-oxyacetoxylation of terminal alkynes is also reported. Ther oles of catalyst, oxidant and other reactionp arameters were evaluated for activation of the unsaturated bond.

Magnetic CuFe2O4 and Fe3O4 Nanoparticles Catalyzed Diacetoxylation of Alkenes and 1,2‐Oxyacetoxylation of Terminal Alkynes Using PhI(OAc)2 as Oxidant

“…The articles published by Gade, and Fujita contain some of the examples for dioxygenation of alkenes using TfOH and BF 3 .OEt 2 , respectively. Recently, we have reported an economical method for diacetoxylation of olefins using a homogeneous iron catalyst i.e Fe(OAc) 2 . Recovery of these homogeneous catalysts have somewhat placed limitations on their general use for large or industrial scale operations.…”

“…We also found that, the use of 3 equivalents of H 2 O consistently provided high yields of 2 a (Table , entry 8). Based on our previous results, at the end of the reaction Ac 2 O was added to the reaction mixture, which enhances the yield of the desired product to 71 % (Table , entry 9). As it is always advisable to compare the reactivity with other reusable catalysts, the same reaction was conducted using nano CuO, Fe 2 O 3 and Fe 3 O 4 (Table , entries 10–12).…”

Neighboring Carbonyl Group Assisted Oxyacetoxylation of Propargylic Carboxylates with Retention of Chirality under Metal Free Condition

“…Many elegant methods are developed using hypervalent iodine affording oxyacetoxylation product through C≡C bond activation . Some of the drawbacks of this strategy involves acetic acid at elevated temperature,– and metal catalysts like Fe and Ag . The first report of a metal free oxidation of alkynes was published by Tamura et al .…”

Preparation of Imidazole Derivatives via Bisfunctionalization of Alkynes Catalyzed by Ruthenium Carbonyl

“…The reaction mechanism for the formation of enediol diacetates and imidazole derivatives (Scheme 5) is proposed on the basis of the literature. 15,19 First, Ru 3 (CO) 12 is oxidized into Ru 2 (CO) 12 Ru(OAc) 2 , followed by complexation with the alkyne to form intermediate A. Due to steric hindrance, OAc adds to the alkyne from the opposite face to the complexed metal catalyst to give B, Ru 3 (CO) 12 is released from B to produce the target product C. Imidazole derivative G is synthesized from C by aminolysis, accompanied by oxidation of the alcohol into an aldehyde, and further condensation, dehydration, and deprotonation.…”

“…7). Moreover, Deng and Luo, 17 Biffis and co-workers, 18 Sreedhar and co-workers, 19 and Bäckvall and co-workers. 20 reported that alkynes reacted with PhI(OAc) 2 to afford -acetoxy ketones catalyzed by AgOAc, CuCl(L)(PPh 3 ), Fe(OAc) 2 , Pd(OAc) 2 , respectively (Scheme 1, eqs.…”