169532-08-5Relevant academic research and scientific papers
Asymmetric inter- and intramolecular cyclopropanations of alkenes catalyzed by rhodium D4-porphyrin: A comparison of rhodium- and ruthenium-centred catalysts
Teng, Pang-Fei,Lai, Tat-Shing,Kwong, Hoi-Lun,Che, Chi-Ming
, p. 837 - 844 (2003)
Iodo-(5,10,15,20-tetrakis(1,2,3,4,5,6,7,8-octahydro-1,4:5,8- dimethanoanthracen-9-yl)porphyrinatorhodium(III), designated as [Rh(P*)(I)], was prepared and its catalytic activity in the asymmetric cyclopropanation of alkenes with ethyl diazoacetate (EDA) w
Synthesis of Forms of a Chiral Ruthenium Complex Containing a Ru-Colefin(sp2) Bond and Their Application to Catalytic Asymmetric Cyclopropanation Reactions
Fujisawa, Ikuhide,Inoue, Hayato,Iwasa, Seiji,Phan Thi Thanh, Nga
supporting information, (2020/02/15)
Organometallic complexes [Ru-Colefin(sp2)-Ru(II)-Pheox 2a-2d] containing a Ru-Colefin(sp2) bond have been prepared from unsaturated chiral oxazoline derivatives and evaluated for asymmetric cyclopropanation reactions. The corresponding optically active cyclopropanes were obtained with high yields and high stereoselectivities (≥99/2) bond. In particular, Ru(II)-Prox catalyst 2c, in which there was no geminal substituent on the metal, was shown to have the highest enantioselectivities.
Stereodivergent Intramolecular Cyclopropanation Enabled by Engineered Carbene Transferases
Chandgude, Ajay L.,Ren, Xinkun,Fasan, Rudi
, p. 9145 - 9150 (2019/06/08)
We report the development of engineered myoglobin biocatalysts for executing asymmetric intramolecular cyclopropanations resulting in cyclopropane-fused γ-lactones, which are key motifs found in many bioactive molecules. Using this strategy, a broad range of allyl diazoacetate substrates were efficiently cyclized in high yields with up to 99% enantiomeric excess. Upon remodeling of the active site via protein engineering, myoglobin variants with stereodivergent selectivity were also obtained. In combination with whole-cell transformations, these biocatalysts enabled the gram-scale assembly of a key intermediate useful for the synthesis of the insecticide permethrin and other natural products. The enzymatically produced cyclopropyl-γ-lactones can be further elaborated to furnish a variety of enantiopure trisubstituted cyclopropanes. This work introduces a first example of biocatalytic intramolecular cyclopropanation and provides an attractive strategy for the stereodivergent preparation of fused cyclopropyl-γ-lactones of high value for medicinal chemistry and the synthesis of natural products.
Reusable and highly enantioselective water-soluble Ru(II)-Amm-Pheox catalyst for intramolecular cyclopropanation of diazo compounds
Mandour, Hamada S.A.,Nakagawa, Yoko,Tone, Masaya,Inoue, Hayato,Otog, Nansalmaa,Fujisawa, Ikuhide,Chanthamath, Soda,Iwasa, Seiji
supporting information, p. 357 - 363 (2019/02/20)
A reusable and highly enantioselective catalyst for the intramolecular cyclopropanation of various diazo ester and Weinreb amide derivatives was developed. The reactions catalyzed by a water-soluble Ru(II)-Amm-Pheox catalyst proceeded smoothly at room temperature, affording the corresponding bicyclic cyclopropane ring-fused lactones and lactams in high yields (up to 99%) with excellent enantioselectivities (up to 99% ee). After screening of various catalysts, the Ru(II)-Amm-Pheox complex having an ammonium group proved to be crucial for the intramolecular cyclopropanation reaction in a water/ether biphasic medium. The water-soluble catalyst could be reused at least six times with little loss in yield and enantioselectivity.
Water-soluble chiral ruthenium(II) phenyloxazoline complex: Reusable and highly enantioselective catalyst for intramolecular cyclopropanation reactions
Abu-Elfotoh, Abdel-Moneim,Nguyen, Diem Phuong Thi,Chanthamath, Soda,Phomkeona, Kesiny,Shibatomi, Kazutaka,Iwasa, Seiji
supporting information, p. 3435 - 3439 (2013/03/13)
The intramolecular cyclopropanation of various trans-allylic diazoacetates and alkenyl diazoketones has been achieved with excellent enantioselectivities of up to 98% ee and in quantitative yields by using a water-soluble ruthenium(II)/hydroxymethyl(phenyl)oxazoline catalyst in a water/ether biphasic medium. The catalyst could be reused at least five times.
Chiral bis(oxazolinyl)phenyl RuII catalysts for highly enantioselective cyclopropanation
Ito, Jun-Ichi,Ujiie, Satoshi,Nishiyama, Hisao
supporting information; experimental part, p. 4986 - 4990 (2010/08/19)
chemical equation presantation Good to excellent enantioselectivities (up to 99 % ee) of trans-cyclopropane derivatives were achieved in the cyclopropanation of alkenes with tert-buty1 α-diazoacetate by using 0.5 mol % of a mononuclear chiral ruthenium aqua complex containing the chiral bis(oxazolinyl)phenyl ligand, which was obtained via C-H activation by RuCl 3·3H2O in the presence of Mg and cyclooctadiene (cod). Intramolecular cyclopropanation reactions using the new Ru complex also proceed with high yields and excellent enantioselectivities.
Asymmetric inter- and intramolecular cyclopropanation reactions catalyzed by a reusable macroporous-polymer-supported chiral ruthenium(II)/phenyloxazoline complex
Abu-Elfotoh, Abdel-Moneim,Phomkeona, Kesiny,Shibatomi, Kazutaka,Iwasa, Seiji
supporting information; experimental part, p. 8439 - 8443 (2011/01/05)
Along came poly: A novel macroporous polymer-supported chiral Ru II/pheox catalyst (1, see SEM image) afforded excellent reactivity and enantioselectivity in inter- and intramolecular cyclopropanation reactions with a broad range of substrates. The catalyst showed no leaching and could be reused up to 11-times, even after storage.
Cis-β-bis(carbonyl) ruthenium-salen complexes: X-ray crystal structures and remarkable catalytic properties toward asymmetric intramolecular alkene cyclopropanation
Xu, Zhen-Jiang,Fang, Ran,Zhao, Cunyuan,Huang, Jie-Sheng,Li, Gong-Yong,et al.
supporting information; scheme or table, p. 4405 - 4417 (2009/09/30)
cis-β-[Ru"(salenA)(CO)2] (salenA =N,N-bis(3-R1-5-R2-salicylidene)-1,2-cyclohexenedi amine di- anion; R1 = R2 = But, 1a;R1 = Prt,R2 = H
Chiral bis(pyridylimino)isoindoles: A highly modular class of pincer ligands for enantioselective catalysis
Langlotz, Bjoern K.,Wadepohl, Hubert,Gade, Lutz H.
supporting information; body text, p. 4670 - 4674 (2009/02/06)
(Chemical Equation Presented) Protect your back: Chiral wedges (red, see scheme) at the wingtips of bis(2-pyridylimino) isoindole (bpi) pincer ligands with an appropriate protective hedge (green), to block the metal center from backside attack, in the backbone represent a new class of efficient 3d-metal catalysts. These catalysts gave excellent enantioselectivities in the iron-catalyzed hydrosilylation of arylketones and in the cobalt-catalyzed cyclopropanation of alkenes.
α-diazoacetates as carbene precursors: Metallosalen-catalyzed asymmetric cyclopropanation
Uchida, Tatsuya,Katsuki, Tsutomu
, p. 1715 - 1723 (2007/10/03)
Readily available α-diazo compounds have been shown to be efficient carbene precursors for asymmetric cyclopropanation using ruthenium(NO)-salen and cobalt-salen complexes, as catalysts. The stereoselectivity of the cyclopropanation depends on the metal i
