Refernces
10.1021/jo00070a022
The research investigates the nickel-mediated cross-coupling of unactivated neopentyl iodides with organozinc reagents, catalyzed by dichloro(1,1'-bis(diphenylphosphino)ferrocene)nickel(II) ((dppf)NiCl2). The study explores the formation of zinc nucleophiles by treating ZnCl2-dioxane with Grignard reagents in an ethereal solvent, finding that the cross-coupling works optimally for diorganozincs formed from aryl chlorides or CH3MgCl, while aryl bromides can cause reduction and/or reductive dimerization of the electrophile. The research highlights that the use of organozincs overcomes many side reactions observed with the (dppf)-NiCl2-mediated cross-coupling of Grignard reagents. The study also examines the effects of varying the halide in the Grignard reagent and the influence of different solvents and catalysts on the reaction outcomes. Key chemicals involved in the research include neopentyl iodides, various Grignard reagents (such as CH3MgCl, PhMgCl, etc.), ZnCl2-dioxane, and (dppf)NiCl2, with the findings suggesting that organomagnesium chlorides are the reagents of choice for achieving higher yields and cleaner reaction mixtures.
10.3390/molecules21111443
The study focuses on the characterization of the O-methyltransferase enzyme JerF, which is involved in the late stages of jerangolid biosynthesis. JerF is unique for its ability to catalyze the formation of a non-aromatic, cyclic methylenolether, a reaction not previously characterized in other O-methyltransferases. The researchers successfully overexpressed JerF in E. coli and utilized cell-free extracts to conduct bioconversion experiments. They also chemically synthesized a range of substrate surrogates to evaluate JerF's catalytic activity and substrate tolerance. The results revealed that JerF has a broad substrate tolerance and high regioselectivity, making it a promising candidate for chemoenzymatic synthesis, particularly for the modification of natural products containing a 4-methoxy-5,6-dihydro-2H-pyran-2-one moiety. The study also highlighted the potential of JerF in introducing specific methylation patterns and its use in biorthogonal coupling reactions, such as click chemistry, for site-specific labeling of biomolecules like DNA, RNA, or proteins.
10.3184/174751911X13182405888457
The research presents a study on the preparation of methyl (2-hydroxynaphthalen-1-yl)(aryl)methyl/benzylcarbamate derivatives using magnesium (II) 2,2,2-trifluoroacetate as an efficient catalyst. The methodology involves multi-component condensation reactions of aldehydes, 2-naphthol, and methyl/benzyl carbamate, resulting in the synthesis of various derivatives in high yields. The catalyst, Mg(OOCCF3)2, was prepared from trifluoroacetic acid and magnesium chloride and characterized through powder X-ray diffraction. The experiments involved optimizing reaction conditions such as catalyst amount, temperature, and solvent, with the best results achieved under solvent-free conditions at 100°C using 0.1 mmol of catalyst. Various aromatic aldehydes were tested, and the reaction was influenced by the electronic and steric properties of the aldehydes. The products were purified by simple filtration and crystallization from ethanol, and their structures were confirmed using NMR and IR spectroscopy, as well as elemental analysis. The study demonstrates an efficient method for synthesizing 1-carbamatoalkyl 2-naphthol derivatives with advantages such as good yields, simple procedure, shorter reaction times, and milder conditions.
10.1016/j.tet.2004.12.059
The research focuses on the preparation of optically active b-hydroxy-b-arylpropionates, d-hydroxy-d-aryl-b-oxo-pentanoates, and their butyryl derivatives via CRL-catalyzed hydrolysis. These chiral compounds are important precursors for various chiral pharmaceuticals and natural products. The study explores the use of Candida Rugosa lipase (CRL) to achieve enantioselective hydrolysis and alcoholysis of these compounds, resulting in high yields and good enantioselectivity. Key chemicals involved in the research include the substrates b-hydroxy-b-arylpropionates and d-hydroxy-d-aryl-b-oxo-pentanoates, as well as reagents such as DCC/butyric acid for butyrylation and MgCl2 for pre-equilibration in the hydrolysis process. The research also involves the use of various solvents like diisopropyl ether and CH2Cl2, and analytical techniques such as IR, NMR, and HPLC to characterize the products and assess their enantioselectivity.
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