Rhodium Porphyrin Catalyzed Regioselective Transfer Hydrogenolysis of C–C σ-Bonds in Cyclopropanes with ⁱPrOH

Abstract

A new rhodium porphyrin catalyzed regioselective transfer hydrogenolysis of both activated and unactivated cyclopropanes employing i PrOH as the hydrogen source was discovered. The reaction mechanism for the C–C σ-bond activation of cyclopropanes was identified through an initial radical substitution with rhodium­(II) metalloporphyrin radical to give a rhodium porphyrin alkyl, followed by hydrogenolysis with i PrOH to give the corresponding acyclic alkanes and regenerate rhodium­(II) metalloporphyrin radical.

Organoselenium-Catalyzed Asymmetric Cyclopropanations of (E)-Chalcones

“…Table reveals that selenide 3a successfully catalyzes the cyclopropanation reaction of ( E )-chalcone 4 and benzyl bromide in acetonitrile, DMF, THF, CH 2 Cl 2 , Et 2 O, and BuOH (entries 1–5 and 7, respectively), leading to cyclopropane 5 (76–91% ee) as the major product along with its diastereomer 5′ (74/26 to 84/16 dr) in 26–90% yield. The absolute structure of 5 was determined by XRD, and the structure of 5′ was identified by comparison with previously reported NMR spectra . On the contrary, 4 and benzyl bromide did not react in toluene or methanol (entries 6 and 9).…”

Palladium-catalyzed stereoselective ring-opening reaction of aryl cyclopropyl ketones

“…The cyclopropyl ring-opening reaction of phenyl cyclopropyl ketone, as a mono-activated cyclopropane, mainly focuses on adding other fragments to obtain saturated three-carbon structures. 5,9,11,15 Nonadditive products obtained by ringopening of phenyl cyclopropyl ketone were rarely reported. Ogoshi et al reported that the reaction of phenyl cyclopropyl ketone with Ni(cod) 2 and PBu 3 at 100 °C in toluene-d 8 gave an η 2 -enonenickel complex.…”

“…8 a The chelating group converts the regioselectivity and facilitates oxidative addition, resulting in faster transformations. Rhodium, 9 nickel, 10 samarium, 11 palladium, 12 tellurium, 13 and tin 14 are commonly used transition metals in this route (Scheme 1).…”

Structure and photophysical and electrochemical properties of a copper porphyrin complex with a three-dimensional framework

“…As far as is known, porphyrins are famous for their vital roles in the red blood cells of animals and the green leaves of plants; as a result, porphyrins have become one of the most widely investigated chemical systems and have drawn much attention as wonderful functional materials. Due to their comparability to the natural photosynthetic chlorophyll pigment, easy preparation, intensive optical absorptions and emissions, long lifetimes of the singlet and triplet states, and favourable redox potential (Kadish et al, 2000;Chambron et al, 2000;Gust & Moore, 2000), porphyrins offer a very versatile synthetic base for many kinds of materials which have different applications in many disciplines of physics and chemistry, such as solar cells and opto-electronics (Khan & Sayyad, 2012;Seol et al, 2012;Arkan et al, 2015;Xia et al, 2015;Ørnsø et al, 2015), catalysis (Chen et al, 2019;Zhang et al, 2018;Mokary Yazdely et al, 2019), sensors (Ma et al, 2019;Wu et al, 2018;Zhao et al, 2019) and molecular sieves (Anjali et al, 2018;Hou et al, 2014).…”