- Anti-Markovnikov alkene oxidation by metal-oxo–mediated enzyme catalysis
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Catalytic anti-Markovnikov oxidation of alkene feedstocks could simplify synthetic routes to many important molecules and solve a long-standing challenge in chemistry. Here we report the engineering of a cytochrome P450 enzyme by directed evolution to catalyze metal-oxo–mediated anti-Markovnikov oxidation of styrenes with high efficiency. The enzyme uses dioxygen as the terminal oxidant and achieves selectivity for anti-Markovnikov oxidation over the kinetically favored alkene epoxidation by trapping high-energy intermediates and catalyzing an oxo transfer, including an enantioselective 1,2-hydride migration. The anti-Markovnikov oxygenase can be combined with other catalysts in synthetic metabolic pathways to access a variety of challenging anti-Markovnikov functionalization reactions.
- Hammer, Stephan C.,Kubik, Grzegorz,Watkins, Ella,Huang, Shan,Minges, Hannah,Arnold, Frances H.
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p. 215 - 218
(2017/10/19)
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- Nucleophilic addition of arylmethylzinc reagents (ArCH2ZnCl) to formaldehyde: An easy access to 2-(hetro)arylethyl alcohols
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The selective addition of arylmethylmagnesium halides with formaldehyde giving arylethyl alcohols is extremely challenging. To circumvent the difficulties, in the current communication, we have reported on the nucleophilic addition of benzyl zinc reagents derived from inexpensive and abundant benzyl chlorides to paraformaldehyde. The reaction investigated herein is hitherto unknown and was found to be selective, operationally simple, atom- and step-economical and high yielding to deliver phenethyl alcohols utilized as key perfumery ingredients in 60–83% yields. After successful establishment of the reaction condition, the reaction was also scaled up successfully to deliver a large-scale preparation of the phenethyl alcohol.
- Bhatt,Samant,Pednekar, Suhas
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supporting information
p. 968 - 974
(2017/05/04)
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- Antiproliferative activity and SARs of caffeic acid esters with mono-substituted phenylethanols moiety
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A series of CAPE derivatives with mono-substituted phenylethanols moiety were synthesized and evaluated by MTT assay on growth of 4 human cancer cell lines (Hela, DU-145, MCF-7 and ECA-109). The substituent effects on the antiproliferative activity were systematically investigated for the first time. It was found that electron-donating and hydrophobic substituents at 2′-position of phenylethanol moiety could significantly enhance CAPE's antiproliferative activity. 2′-Propoxyl derivative, as a novel caffeic acid ester, exhibited exquisite potency (IC50?=?0.4?±?0.02 & 0.6?±?0.03?μM against Hela and DU-145 respectively).
- Xie, Jin,Yang, Fengzhi,Zhang, Man,Lam, Celine,Qiao, Yixue,Xiao, Jia,Zhang, Dongdong,Ge, Yuxuan,Fu, Lei,Xie, Dongsheng
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p. 131 - 134
(2016/12/27)
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- Direct Ruthenium-Catalyzed Hydrogenation of Carboxylic Acids to Alcohols
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The "green" reduction of carboxylic acids to alcohols is a challenging task in organic chemistry. Herein, we describe a general protocol for generation of alcohols by catalytic hydrogenation of carboxylic acids. Key to success is the use of a combination of Ru(acac)3, triphos and Lewis acids. The novel method showed broad substrate tolerance and a variety of aliphatic carboxylic acids including biomass-derived compounds can be smoothly reduced.
- Cui, Xinjiang,Li, Yuehui,Topf, Christoph,Junge, Kathrin,Beller, Matthias
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supporting information
p. 10596 - 10599
(2015/09/02)
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- N-(phenylselenomethyl)phthalimide as new reagent for mild protection of alcohols as Pim-ethers
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A mild activation of N-(phenylselenomethyl)phthalimide by iodonium ion in the presence of alcohols to give the corresponding O-phthalimidomethyl derivatives (Pim-ethers) is provided. Simple cleavage of the phthalimido group with ethylenediamine is also reported thus making this approach a new and efficient method of protecting alcohols.
- Temperini, Andrea,Minuti, Lucio
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scheme or table
p. 2709 - 2711
(2012/07/16)
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- Exploiting self-assembly for ligand-scaffold optimization: Substrate-tailored ligands for efficient catalytic asymmetric hydroboration
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(Chemical Equation Presented) Mix and match: A self-assembled ligand library (SAL XY) affords a wide range of R/S ratios in Rh-catalyzed asymmetric hydroboration (see scheme; nbd = 2,5-norbornadiene, R* is a chiral substituent). Ligand-scaffold optimization reveals "substrate- tailored" ligands that afford high regio- and enantioselectivity for a variety of ortho-substituted styrene derivatives.
- Moteki, Shin A.,Takacs, James M.
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p. 894 - 897
(2008/09/20)
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- Regioselective hydroboration-oxidation and -amination of fluoro-substituted styrenes
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Hydroboration of fluorinated styrenes with common hydroborating agents results in polymerization. However, regioselective hydroboration has been achieved by utilizing iodoborane-dimethyl sulfide. A series of fluorinated β-phenethyl alcohols and amines were synthesized via this methodology.
- Ramachandran, P. Veeraraghavan,Madhi, Sateesh,O'Donnell, Martin J.
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p. 1252 - 1255
(2008/09/20)
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- New C2-symmetrical 1,2-diphosphanes for the efficient rhodium-catalyzed asymmetric hydroboration of styrene derivatives
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A double [2,3] sigmatropic rearrangement enables the fast synthesis of novel C2-symmetrical 1,2-diphosphanes in good yields. These phosphanes (for example, 1; c-Hex = cyclohexyl) are highly efficient ligands for the rhodium-catalyzed asymmetric hydroboration of a wide variety of styrenes (see scheme). cod = 1,5-cyclooctadiene; DME = 1,2-dimethoxyethane.
- Demay, Steandphane,Volant, Florence,Knochel, Paul
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p. 1235 - 1238
(2007/10/03)
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