79981-48-9Relevant academic research and scientific papers
On the mechanism of cytochrome P450-catalyzed oxidations: Reaction of a new enzyme model with a radical clock
Sbaragli, Laura,Woggon, Wolf-D.
, p. 1538 - 1542 (2005)
trans-2-Phenyl-methylcyclopropane was oxidized using PhIO and a P450 enzyme model carrying a SO3- ligand coordinating to iron. Analysis of the product distribution revealed a ratio of 9:1 of the non-rearranged cyclopropyl methanol 18
Radical clock substrate probes and kinetic isotope effect studies of the hydroxylation of hydrocarbons by methane monooxygenase
Liu, Katherine E.,Johnson, Cathy C.,Newcomb, Martin,Lippard, Stephen J.
, p. 939 - 947 (1993)
Four mechanistic probes, trans-2-phenylmethylcyclopropane (1), 2,2-diphenylmethylcyclopropane (2), trans-1,2-dimethylcyclopropane (3), and bicyclo[2.1.0]pentane (4), were used as substrates to investigate the possible formation of radical intermediates in
Erratum: Cu-Catalyzed Three-Component Carboamination of Alkenes (J. Am. Chem. Soc. (2018) 140:1 (58?61) DOI: 10.1021/jacs.7b10529)
Gockel, Samuel N.,Buchanan, Travis L.,Hull, Kami L.
supporting information, p. 6019 - 6020 (2021/05/13)
Pages 59 and 60. We have identified an error in the structural analysis of compounds presented in our publication detailing. (Table presented).
A Vinyl Cyclopropane Ring Expansion and Iridium-Catalyzed Hydrogen Borrowing Cascade
Cheong, Choon Boon,Christensen, Kirsten E.,Donohoe, Timothy J.,Frost, James R.,Wübbolt, Simon
supporting information, p. 11339 - 11344 (2020/05/25)
A vinyl cyclopropane rearrangement embedded in an iridium-catalyzed hydrogen borrowing reaction enabled the formation of substituted stereo-defined cyclopentanes from Ph* methyl ketone and cyclopropyl alcohols. Mechanistic studies provide evidence for the ring-expansion reaction being the result of a cascade based on oxidation of the cyclopropyl alcohols, followed by aldol condensation with the pentamethyl phenyl-substituted ketone to form an enone containing the vinyl cyclopropane. Subsequent single electron transfer (SET) to this system initiates a rearrangement, and the catalytic cycle is completed by reduction of the new enone. This process allows for the efficient formation of diversely substituted cyclopentanes as well as the construction of complex bicyclic carbon skeletons containing up to four contiguous stereocentres, all with high diastereoselectivity.
Cooperative NHC and Photoredox Catalysis for the Synthesis of β-Trifluoromethylated Alkyl Aryl Ketones
D?ben, Nadine,Meng, Qing-Yuan,Studer, Armido
supporting information, p. 19956 - 19960 (2020/09/04)
Despite the great potential of radical chemistry in organic synthesis, N-heterocyclic carbene (NHC)-catalyzed reactions involving radical intermediates are not well explored. This communication reports the three-component coupling of aroyl fluorides, styrenes and the Langlois reagent (CF3SO2Na) to give various β-trifluoromethylated alkyl aryl ketones with good functional group tolerance in moderate to high yields by cooperative photoredox/NHC catalysis. The alkene acyltrifluoromethylation proceeds via radical/radical cross coupling of ketyl radicals with benzylic C-radicals. The ketyl radicals are generated via SET reduction of in situ formed acylazolium ions whereas the benzylic radicals derive from trifluoromethyl radical addition onto styrenes.
Enantioselective Remote C(sp3)-H Cyanation via Dual Photoredox and Copper Catalysis
Chen, Hui,Jin, Weiwei,Yu, Shouyun
supporting information, p. 5910 - 5914 (2020/08/12)
The remote C(sp3)-H cyanation of carboxamides has been described by merging photoredox and copper catalysis in a site-selective and enantiocontrolled manner. The protocol is the integration of photoinduced and nitrogen-centered radical-mediated intermolecular hydrogen atom transfer with chiral copper-complex-catalyzed radical cyanation. This strategy gives enantio-enriched cyanated amides in high yields.
Donor-Acceptor Bicyclopropyls as 1,6-Zwitterionic Intermediates: Synthesis and Reactions with 4-Phenyl-1,2,4-triazoline-3,5-dione and Terminal Acetylenes
Potapov, Konstantin V.,Denisov, Dmitry A.,Glushkova, Valeriia V.,Novikov, Roman A.,Tomilov, Yury V.
, p. 15562 - 15576 (2020/11/30)
The bicyclopropyl system activated by incorporation of donor and acceptor groups in the presence of Lewis acids was used as a synthetic equivalent of 1,6-zwitterions. Opening of both cyclopropane rings in 2′-aryl-1,1′-bicyclopropyl-2,2-dicarboxylates (D-A bicyclopropyl, ABCDs) in the presence of GaI3 + Bu4N+GaI4- results in 5-iodo-5-arylpent-2-enylmalonates as products of HI formal 1,6-addition to the bicyclopropyl system. The use of GaCl3 or GaBr3 as a Lewis acid and terminal aryl or alkyl acetylenes as 1,6-zwitterion interceptors allows the alkyl substituent to be grown to give the corresponding acyclic 7-chloro(bromo)-hepta-2,6-dienylmalonates. The reaction of ABCDs with 4-phenyl-1,2,4-triazoline-3,5-dione (PTAD) catalyzed by Yb(OTf)3 also results in the opening of both cyclopropane rings. The reaction products are tetrahydropyridazine derivatives - (7,9-dioxo-1,6,8-triazabicyclo[4.3.0]non-3-en-2-ylmethyl)malonates - containing one more PTAD moiety in the malonyl group.
Metal-free domino Cloke-Wilson rearrangement-hydration-dimerization of cyclopropane carbaldehydes: A facile access to oxybis(2-aryltetrahydrofuran) derivatives
Banerjee, Prabal,Dey, Raghunath,Rajput, Shruti
, (2020/03/13)
In this work, we have demonstrated a metal-free transformation of cyclopropane carbaldehydes to oxybis(2-aryltetrahydrofuran) derivatives via a domino Cloke-Wilson rearrangement-hydration-dimerization sequence. Commercially inexpensive p-toluene sulfonic acid (PTSA) was used as a Br?nsted acid catalyst, and reactions were conducted in an open-flask. Detection of reaction intermediates were carried to get an insight into the reaction pathway.
Regioselective Br?nsted Acid-Catalyzed Annulation of Cyclopropane Aldehydes with N′-Aryl Anthranil Hydrazides: Domino Construction of Tetrahydropyrrolo[1,2- a]quinazolin-5(1 H)ones
Banerjee, Prabal,Kaur, Navpreet,Singh, Priyanka
, p. 3393 - 3406 (2020/03/23)
A highly regioselective synthesis of tetrahydropyrrolo[1,2-a]quinazolin-5(1H)one derivatives was achieved by reacting cyclopropane aldehydes with N′-aryl anthranil hydrazides in the presence of p-toluene sulfonic acid (PTSA). The transformation involves domino imine formation and intramolecular cyclization to form 2-arylcyclopropyl-2,3-dihydroquinolin-4(1H)-one, followed by nucleophilic ring opening of the cyclopropyl ring to form desired tetrahydropyrrolo[1,2-a]quinazolin-5(1H)one in good to excellent yield with complete regioselectivity. This protocol tolerates a great variety of functional groups and thus provides a simple and step-efficient method for pyrroloquinazolinone synthesis.
Accessing dihydro-1,2-oxazine via cloke-wilson-type annulation of cyclopropyl carbonyls: application toward the diastereoselective synthesis of pyrrolo[1,2- b][1,2]oxazine
Banerjee, Prabal,Kumar, Pankaj,Kumar, Rakesh
, p. 6535 - 6550 (2020/06/09)
A convenient additive-free synthesis of dihydro-4H-1,2-oxazines via a Cloke-Wilson-type ring expansion of the aryl-substituted cyclopropane carbaldehydes with the hydroxylamine salt is introduced. Comparatively less active cyclopropyl ketones also follow a similar protocol if supplemented by catalytic p-toluene sulfonic acid monohydrate. The transformation is performed in an open-to-air flask as it shows negligible sensitivity toward air/moisture. Dihydro-4H-1,2-oxazines when subjected to cycloaddition with the cyclopropane diester afford a trouble-free formulation of the valued hexahydro-2H-pyrrolo[1,2-b][1,2]oxazine derivatives. A cascade one-pot variant of this two-step strategy offers a comparable overall yield of the final product.
