6142-64-9Relevant articles and documents
Selective carbene transfer to amines and olefins catalyzed by ruthenium phthalocyanine complexes with donor substituents
Cailler, Lucie P.,Kroitor, Andrey P.,Martynov, Alexander G.,Gorbunova, Yulia G.,Sorokin, Alexander B.
supporting information, p. 2023 - 2031 (2021/02/26)
Electron-rich ruthenium phthalocyanine complexes were evaluated in carbene transfer reactions from ethyl diazoacetate (EDA) to aromatic and aliphatic olefins as well as to a wide range of aromatic, heterocyclic and aliphatic amines for the first time. It was revealed that the ruthenium octabutoxyphthalocyanine carbonyl complex [(BuO)8Pc]Ru(CO) is the most efficient catalyst converting electron-rich and electron-poor aromatic olefins to cyclopropane derivatives with high yields (typically 80-100%) and high TON (up to 1000) under low catalyst loading and nearly equimolar substrate/EDA ratio. This catalyst shows a rare efficiency in the carbene insertion into amine N-H bonds. Using a 0.05 mol% catalyst loading, a high amine concentration (1 M) and 1.1 eq. of EDA, a number of structurally divergent amines were selectively converted to mono-substituted glycine derivatives with up to quantitative yields and turnover numbers reaching 2000. High selectivity, large substrate scope, low catalyst loading and practical reaction conditions place [(BuO)8Pc]Ru(CO) among the most efficient catalysts for the carbene insertion into amines.
Comparative Study of the Electronic Structures of μ-Oxo, μ-Nitrido, and μ-Carbido Diiron Octapropylporphyrazine Complexes and Their Catalytic Activity in Cyclopropanation of Olefins
Cailler, Lucie P.,Clémancey, Martin,Barilone, Jessica,Maldivi, Pascale,Latour, Jean-Marc,Sorokin, Alexander B.
, p. 1104 - 1116 (2020/02/04)
The electronic structure of three single-Atom bridged diiron octapropylporphyrazine complexes (FePzPr8)2X having Fe(III)-O-Fe(III), Fe(III)-N-Fe(IV) and Fe(IV)-C-Fe(IV) structural units was investigated by M?ssbauer spectroscopy and density functional theory (DFT) calculations. In this series, the isomer shift values decrease, whereas the values of quadrupole splitting become progressively greater indicating the increase of covalency of Fe-X bond in the μ-oxo, μ-nitrido, μ-carbido row. The M?ssbauer data point to low-spin systems for the three complexes, and calculated data with B3LYP-D3 show a singlet state for μ-oxo and μ-carbido and a doublet state for μ-nitrido complexes. An excellent agreement was obtained between B3LYP-D3 optimized geometries and X-ray structural data. Among (FePzPr8)2X complexes, μ-oxo diiron species showed a higher reactivity in the cyclopropanation of styrene by ethyl diazoacetate to afford a 95% product yield with 0.1 mol % catalyst loading. A detailed DFT study allowed to get insight into electronic structure of binuclear carbene species and to confirm their involvement into carbene transfer reactions.
Iron/N-doped graphene nano-structured catalysts for general cyclopropanation of olefins
Bartling, Stephan,Beller, Matthias,Ferretti, Francesco,Formenti, Dario,Junge, Kathrin,Kreyenschulte, Carsten,Ragaini, Fabio,Sarkar, Abhijnan
, p. 6217 - 6221 (2020/08/24)
The first examples of heterogeneous Fe-catalysed cyclopropanation reactions are presented. Pyrolysis of in situ-generated iron/phenanthroline complexes in the presence of a carbonaceous material leads to specific supported nanosized iron particles, which are effective catalysts for carbene transfer reactions. Using olefins as substrates, cyclopropanes are obtained in high yields and moderate diastereoselectivities. The developed protocol is scalable and the activity of the recycled catalyst after deactivation can be effectively restored using an oxidative reactivation protocol under mild conditions. This journal is
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.
Multigram Synthesis and C?C/C?N Couplings of Functionalized 1,2-Disubstituted Cyclopropyltrifluoroborates
Hryschuk, Oleksandr V.,Yurov, Yevhen,Tymtsunik, Andriy V.,Kovtunenko, Volodymyr O.,Komarov, Igor V.,Grygorenko, Oleksandr O.
, p. 5428 - 5439 (2019/11/14)
A convenient approach to the multigram synthesis of functionalized 1,2-disubstituted cyclopropyltrifluoroborates was developed, based on Pd(II)- or Cu(I)-catalyzed reaction of vinyltrifluoroborate and diazo compounds. Optimized protocols allowed for the preparation of the target products as pure diastereomers on multigram scale. It was shown that the title compounds were good coupling partners for the Suzuki-Miyaura and Chan-Lam reactions, which provide medicinally relevant (het)arylcyclopropanes with high diastereoselectivity. (Figure presented.).
Metal-Free Ring Opening Cyclization of Cyclopropane Carbaldehydes and N-Benzyl Anilines: An Eco-Friendly Access to Functionalized Benzo[b]azepine Derivatives
Dey, Raghunath,Banerjee, Prabal
, p. 2849 - 2854 (2019/04/26)
Herein, we report a p-toluenesulfonic acid (PTSA) initiated mild and user-friendly ring opening/domino ring opening cyclization reaction (depends on substituent present in N-benzyl aniline) of cyclopropane carbaldehyde and N-benzyl aniline towards the formation of substituted 4-amino butanal/2,3-dihydro-1H-benzo[b]azepine. The product dihydro-1H-benzo[b]azepine was also converted into the corresponding tetrahydro-1H-benzo[b]azepine. (Figure presented.).
An Artificial Heme Enzyme for Cyclopropanation Reactions
Villarino, Lara,Splan, Kathryn E.,Reddem, Eswar,Alonso-Cotchico, Lur,Gutiérrez de Souza, Cora,Lledós, Agustí,Maréchal, Jean-Didier,Thunnissen, Andy-Mark W. H.,Roelfes, Gerard
supporting information, p. 7785 - 7789 (2018/06/04)
An artificial heme enzyme was created through self-assembly from hemin and the lactococcal multidrug resistance regulator (LmrR). The crystal structure shows the heme bound inside the hydrophobic pore of the protein, where it appears inaccessible for substrates. However, good catalytic activity and moderate enantioselectivity was observed in an abiological cyclopropanation reaction. We propose that the dynamic nature of the structure of the LmrR protein is key to the observed activity. This was supported by molecular dynamics simulations, which showed transient formation of opened conformations that allow the binding of substrates and the formation of pre-catalytic structures.
Cyclopropanation of alkenes with metallocarbenes generated from monocarbonyl iodonium ylides
Chidley, Tristan,Murphy, Graham K.
supporting information, p. 8486 - 8490 (2018/12/01)
Reacting Wittig reagents and the hypervalent iodine reagent iodosotoluene, in the presence of 10 mol% Cu(tfacac)2 and 5 equiv. of alkene, results in a novel cyclopropanation reaction. The reagent combination is believed to generate a transient monocarbonyl iodonium ylide (MCIY) in situ, which can be intercepted by the copper catalyst to give a metallocarbene. Both ester and ketone derived phosphoranes can be used, as can styrenyl and non-styrenyl alkenes, which provides cyclopropanes in yields up to 81%.
