34702-96-0Relevant academic research and scientific papers
Enzyme stabilization via computationally guided protein stapling
Moore, Eric J.,Zorine, Dmitri,Hansen, William A.,Khare, Sagar D.,Fasan, Rudi
, p. 12472 - 12477 (2017)
Thermostabilization represents a critical and often obligatory step toward enhancing the robustness of enzymes for organic synthesis and other applications. While directed evolution methods have provided valuable tools for this purpose, these protocols are laborious and time-consuming and typically require the accumulation of several mutations, potentially at the expense of catalytic function. Here, we report a minimally invasive strategy for enzyme stabilization that relies on the installation of genetically encoded, nonreducible covalent staples in a target protein scaffold using computational design. This methodology enables the rapid development of myoglobin-based cyclopropanation biocatalysts featuring dramatically enhanced thermostability (ΔTm = +18.0°C and ΔT50 = +16.0°C) as well as increased stability against chemical denaturation [ΔCm (GndHCl) = 0.53 M], without altering their catalytic efficiency and stereoselectivity properties. In addition, the stabilized variants offer superior performance and selectivity compared with the parent enzyme in the presence of a high concentration of organic cosolvents, enabling the more efficient cyclopropanation of a water-insoluble substrate. This work introduces and validates an approach for protein stabilization which should be applicable to a variety of other proteins and enzymes.
Catalytic cyclopropanation, antimicrobial, and DFT properties of some chelated transition metal(II) complexes
Ababneh, Taher S.,Al-Dawood, Lina A.,Al-Momani, Waleed M.,Hijazi, Ahmed K.,Taha, Ziyad A.
, (2021)
Transition Metal (II) complexes of general formula [MII(NH2C2H4NH2)3][B(C6F5)4]2 (1-6), where (M= Mn, Fe, Co, Ni, Cu, Zn) have been synthesized and characterized in the solid state and in solution using elemental, thermogravimetric analysis, EPR, 11B-NMR and IR spectroscopy. All complexes were used as catalysts for the cyclopropanation reaction with a variety of olefins. Excellent yields up to 93% were obtained using complex 5. All prepared complexes were used as anti-bacterial agents against different types of bacteria (Gram-negative and Gram-positive), and as anti-fungal agents. Complex 6 showed the highest activity with MIC value of 8 μg/mL against Staphylococcus aureus (Gram-positive bacteria), and of 16 μg/mL against candida albicans. To get more insights into their structural features, molecular geometries of all prepared complexes were fully optimized using density functional theory calculations at the M06-2X/6-311+G** level of theory.
Photoswitching of stereoselectivity in catalysis using a copper dithienylethene complex
Sud, David,Norsten, Tyler B.,Branda, Neil R.
, p. 2019 - 2021 (2005)
(Chemical Equation Presented) Light controls the outcome of a stereoselective reaction. Only in the ring-open form can the shown chelate copper(I) complex transfer its chirality to the cyclopropanation of styrene with ethyl diazoacetate. Irradiation with UV light triggers the ring-closing reaction of the ligand rendering it ineffective (see scheme).
Highly efficient and enantioselective cyclopropanation of styrene with diazoacetates using a new copper-(Schiff-base) catalyst
Li, Zhengning,Zheng, Zhuo,Chen, Huilin
, p. 1157 - 1163 (2000)
A new copper-(Schiff-base) complex, derived from (S)-2-amino-1,1-di(3,5-di-t-butylphenyl)propanol, 2-hydroxy-5-nitrobenzaldehyde and copper acetate monohydrate, was used as an efficient catalyst for the cyclopropanation of styrene with diazoacetates, affo
Electrostatic immobilization of bis(oxazoline)-copper complexes on mesoporous crystalline materials: Cation exchange vs. incipient wetness methods
Feldman, Robert A.,Fraile, José M.
, p. 67 - 73 (2014)
Chiral copper complexes with bis(oxazoline) and azabis(oxazoline) ligands have been immobilized by non-covalent interactions on mesoporous materials. The presence of negative charges achieved by the isomorphous substitution of silicon by aluminium is required to retain the complexes on the support. Cation-exchange was found to be not as efficient as observed with layered clays, and produce catalysts which lose their chiral ligand and give low enantioselectivity. A method employing incipient wetness produces more stable catalysts, whose activity varies to some extent according to the structure of the mesoporous material on which it is supported, and the nature of the chiral ligand.
Asymmetric Cyclopropanation Catalyzed by a Series of Copper-(Schiff-Base) Complexes with Two Chiral Centers
Jiang, Changsheng,Ming, Zhang,Tan, Qitao,Qian, Dai,You, Tianpa
, p. 287 - 294 (2002)
A series of copper-(Schiff-base) complexes with two chiral centers derived from 1,2-diphenyl-2-amino-ethnaol were synthesized and applied to catalyze the asymmetric cyclopropanation of ethenes with diazoacetates. A mechanism that can explain the observed
High-valent tin(IV) porphyrins: Efficient and selective catalysts for cyclopropanation of styrene derivatives with EDA under mild conditions
Gharaati, Shadab,Moghadamb, Majid,Tangestaninejad, Shahram,Mirkhani, Valiollah,Mohammadpoor-Baltork, Iraj,Barati, Behjat,Sadegh, Faranaz
, p. 78 - 82 (2013)
An efficient and selective method for cyclopropanation of styrene derivatives with ethyl diazoacetate (EDA) catalyzed by tin(IV) tetraphenylporphyrinato trifluoromethanesulfonate, [SnIV(TPP)(OTf)2], and tin(IV)tetraphenylporphyrinato tetrafluoroborate, [SnIV(TPP)(BF 4)2] is reported. These electron-deficient catalysts catalyzed the cyclopropanation of styrene derivatives in high yields and short reaction times under mild conditions. The reactions were highly selective and only trans-isomers were produced. Electron-rich styrenes were reacted faster than electron-poor ones. The catalysts were reused several times without loss of their catalytic activity and diastereoselectivity.
Design of a new class of chiral C2-symmetric dipyridylmethane ligands and their application in asymmetric catalysis
Chelucci, Giorgio,Loriga, Giovanni,Murineddu, Gabriele,Pinna, Gerard A.
, p. 8599 - 8602 (2002)
A new class of chiral C2-symmetric dipyridylmethane ligands was prepared from naturally occurring monoterpenes, according to a method based on a double Michael-azaannellation-aromatization sequence. These ligands were assessed in the enantiosel
A non-fluorous copper catalyst for the styrene cyclopropanation reaction in a fluorous medium
Urbano, Juan,Izarra, Rocio,Gomez-Ariza, Jose Luis,Trofimenko, Swiatoslaw,Diaz-Requejo, M. Mar,Perez, Pedro J.
, p. 1000 - 1002 (2006)
The complex TpBr3Cu(NCMe) (1), containing no fluorine atoms, can be dissolved in the perfluoropolyether FOMBLIN and employed as a catalyst for the styrene cyclopropanation reaction with ethyl diazoacetate, with activities and diastereoselectivities identical to those observed under homogeneous conditions with the advantage of being able to use a fluorous separation technique for catalyst recycling. The Royal Society of Chemistry 2006.
Cu(i) catalysed cyclopropanation with enantiopure scorpionate type ligands derived from (+)-camphor or (-)-menthone
Godau, Tom,Bleifuss, Sascha M.,Mueller, Astrid L.,Roth, Thomas,Hoffmann, Susanne,Heinemann, Frank W.,Burzlaff, Nicolai
, p. 6547 - 6554 (2011)
One-pot syntheses of three new enantiopure heteroscorpionate ligands derived from (+)-camphor or (-)-menthone are described. The ligands are obtained by reacting pyrazoles derived from (+)-camphor or (-)-menthone with sodium hydride and thionyl chloride. Subsequent reactions with pyridine and various aldehydes afford the tripod ligands in multi-gram amounts. Especially the menthopyrazole based ligand 6 showed encouraging ee values up to 69% in the Cu(i) catalysed enantioselective cyclopropanation of styrene with ethyl diazoacetate.
