- Selective carbene transfer to amines and olefins catalyzed by ruthenium phthalocyanine complexes with donor substituents
-
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.
- Cailler, Lucie P.,Kroitor, Andrey P.,Martynov, Alexander G.,Gorbunova, Yulia G.,Sorokin, Alexander B.
-
supporting information
p. 2023 - 2031
(2021/02/26)
-
- 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
-
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.
- Cailler, Lucie P.,Clémancey, Martin,Barilone, Jessica,Maldivi, Pascale,Latour, Jean-Marc,Sorokin, Alexander B.
-
p. 1104 - 1116
(2020/02/04)
-
- C-2/C-3 annulation and C-2 alkylation of indoles with 2- alkoxycyclopropanoate esters
-
The annulation reaction between various indoles and 2-alkoxycyclopropanoate esters is reported. Both high efficiency and complete stereochemical control were observed in some cases with this annulation process. A single stereocenter on the cyclopropane controls the diastereoselective formation of up to four new stereocenters. A different reaction course was observed with 3-substituted indole substrates, and an intervening C-3 to C-2-migration process arose that gives synthetically useful C-2 alkylation indole products.
- Bajtos, Barbora,Yu, Ming,Zhao, Hongda,Pagenkopf, Brian L.
-
p. 9631 - 9634
(2008/03/11)
-
- Mechanism of the N-cyclopropylimine-1-pyrroline photorearrangement
-
We present here a combined experimental and computational investigation into the photorearrangement of N-cyclopropylimines to yield pyrrolines. We show that the photochemistry, regiochemistry, and stereochemistry of the reaction can be understood in terms of a mechanism involving barrierless evolution in three different (S2, S1, S0) singlet states and sequential decay through two different (S2/S1, and S 1/S0) conical intersection funnels. We provide evidence that the reaction mechanism involves the generation of a nonequilibrated (i.e., transient) excited state diradical, whose decay can lead not only to pyrrolines but also to cyclopropylimine isomers. It is concluded that the reaction outcome depends on the details of the structure of such transient diradical and on the nature of the dynamics of its decay through the S1/S0 conical intersection.
- Sampedro, Diego,Soldevilla, Alberto,Rodriguez, Miguel A.,Campos, Pedro J.,Olivucci, Massimo
-
p. 441 - 448
(2007/10/03)
-
- Synthesis of Fused Tetrahydrofuran-γ-lactone Motifs via One-Pot Ring Expansion of Cyclopropane Rings
-
An efficient method for constructing fused tetrahydrofuran-γ-lactone scaffolds, such as 8, is presented. Key to this strategy is an acid-catalyzed ring expansion of cyclopropyl precursor 6 that proceeds in the presence of MeSO3H in acetone and produces th
- Kom, Charles,Brady, Thomas,Kim, Sun Hee,Theodorakis, Emmanuel A.
-
p. 1951 - 1966
(2007/10/03)
-
- A Powerful New Strategy for Diversity-Oriented Synthesis of Pyrroles from Donor-Acceptor Cyclopropanes and Nitriles
-
(Equation presented) Lewis acid activated donor-acceptor cyclopropanes react with aliphatic, aromatic, and α,β-unsaturated nitriles in a novel cascade [3 + 2] dipolar cycloaddition, dehydration, and tautomerization sequence to afford pyrroles in moderate
- Yu, Ming,Pagenkopf, Brian L.
-
p. 5099 - 5101
(2007/10/03)
-
- Copper(I)-homoscorpionate catalysts for the preferential, kinetically controlled cis cyclopropanation of α-olefins with ethyl diazoacetate
-
In situ prepared copper catalysts TpxCu (Tpx = homoscorpionate) catalyze the olefin cyclopropanation reaction using ethyl diazoacetate as the carbene source. Very high values of both activity and diastereoselectivity toward the cis isomer have been obtained for styrene, α-methylstyrene, 1-hexene, 1-octene, vinyl acetate, n-butyl vinyl ether, 2,5-dimethyl-2,4-hexadiene, and 3,3-dimethyl-1-butene. The effect of the temperature in the diastereoselectivity was almost negligible within the range -10 to +30°C. Kinetic studies have allowed us to propose that the homoscorpionate ligand might act in a dihapto form during the catalytic process. This transformation seems to operate under kinetic control, where the formation of the cis isomer would govern the reaction rate.
- Diaz-Requejo, M. Mar,Caballero, Ana,Belderrain, Tomas R.,Nicasio, M. Carmen,Trofimenko, Swiatoslaw,Perez, Pedro J.
-
p. 978 - 983
(2007/10/03)
-
- Platinum-catalysed cyclopropanation of olefins with ethyl diazoacetate
-
The addition of ethyl diazoacetate to olefins in the presence of a catalytic amount of platinum complexes provides the corresponding cyclopropanes in good to excellent yields.
- Boverie,Simal,Demonceau,Noels,Eremenko,Sidorov,Nefedov
-
p. 7543 - 7546
(2007/10/03)
-
- Cyclopropanation reactions catalysed by rhodium(I) complexes with new anionic carborane phosphine ligands
-
The first set of rhodium(I) complexes 1-3 has been shown to be active for the cyclopropanation of olefins with diazoaeetates.
- Demonceau,Simal,Noels,Vinas,Nunez,Teixidor
-
p. 7879 - 7882
(2007/10/03)
-
- Olefin cyclopropanation reactions catalysed by novel ruthenacarborane clusters
-
Novel ruthenacarborane clusters exhibit high activity as cyclopropanation catalysts in reactions between ethyl diazoacetate and alkenes.
- Demonceau,Saive,De Froidmont,Noels,Hubert,Chizhevsky,Lobanova,Bregadze
-
p. 2009 - 2012
(2007/10/02)
-
- ENHANCEMENT OF STEREOSELECTIVITY IN CATALYTIC CYCLOPROPANATION REACTIONS
-
Significat enhancement of trans(anti) stereoselectivity is achieved in rhodium(II) acetamide catalyzed cyclopropanation reactions of 2,3,4-trimethyl-3-pentyl diazoacetate (ODA) and diazoacetamides.
- Doyle, Michael P.,Loh, Kuo-Liang,DeVries, Keith M.,Chinn, Mitchell S.
-
p. 833 - 836
(2007/10/02)
-
- EXCEPTIONALLY EFFECTIVE CATALYSIS OF CYCLOPROPANATION REACTIONS BY THE HEXARHODIUM CARBONYL CLUSTER
-
Hexadecacarbonylhexarhodium exhibits exceptional activity as a cyclopropanation catalyst in reactions between ethyl diazoacetate and alkenes that are remarkably free of competing processes.
- Doyle, Michael P.,Tamblyn, William H.,Buhro, William E.,Dorow, Roberta L.
-
p. 1783 - 1786
(2007/10/02)
-