نتایج جستجو برای: lewis protic acid

تعداد نتایج: 762593  

Journal: :Journal of the American Chemical Society 2008
Ciby J Abraham Daniel H Paull Tefsit Bekele Michael T Scerba Travis Dudding Thomas Lectka

We report a detailed synthetic and mechanistic study of an unusual bifunctional, sequential hetero-Diels-Alder/ring-opening reaction in which chiral, metal complexed ketene enolates react with o-quinones to afford highly enantioenriched, alpha-hydroxylated carbonyl derivatives in excellent yield. A number of Lewis acids were screened in tandem with cinchona alkaloid derivatives; surprisingly, t...

2014
Masakatsu Shibasaki Naoya Kumagai

From the synthetic point of view, organic synthesis via catalytic processes offers many benefits. Catalysis frequently obviates the excessive use of the activating reagents and associated tedious purification processes, thereby offering more environmentally benign synthetic processes. Furthermore, the specific activation mode of a catalyst allows for highly chemoselective transformations that a...

2010
Yonathan Dattner Orly Yadid-Pecht

This study presents the fabrication of a low cost poly-acrylic acid (PAA) based emission filter integrated with a low light CMOS contact imager for fluorescence detection. The process involves the use of PAA as an adhesive for the emission filter. The poly-acrylic solution was chosen due its optical transparent properties, adhesive properties, miscibility with polar protic solvents and most imp...

Journal: :Chemical communications 2006
Dipti Patel Stephen T Liddle Shaheed A Mungur Mark Rodden Alexander J Blake Polly L Arnold

Lewis acidic yttrium(III) and titanium(IV) derivatives of anionic, metal-tethered carbenes apparently act as bifunctional catalysts for the polymerisation of D,L-lactide, using a combination of Lewis acid and base functionalities to initiate ring opening of the cyclic monomer; the alcohol- and amino-functionalised carbenes from which they derive provide models for the first insertion step, and ...

2013
Dominik Pfaff Gregor Nemecek Joachim Podlech

Carbonitriles and alcohols react in a Lewis acid-promoted Pinner reaction to carboxylic esters. Best results are obtained with two equivalents of trimethylsilyl triflate as Lewis acid. Good yields are achieved with primary alcohols and aliphatic or benzylic carbonitriles, but the straightforward synthesis of acrylates and benzoates starting with acrylonitrile and benzonitrile, respectively, is ...

Journal: :Molecules 2006
Akihiro Yoshida Xiuhua Hao Osamu Yamazaki Joji Nishikido

Organic synthetic methodology in the 21st century aims to conform to the principles of green sustainable chemistry (GSC) and we may expect that in the future, the realization of GSC will be an important objective for chemical industries. An important aim of synthetic organic chemistry is to implement waste-free and environmentally-benign industrial processes using Lewis acids as versatile as al...

Journal: :Chemical & pharmaceutical bulletin 2000
S Yamada H Suemune

The reactivity of 3-substituted 4-methyl-4-(3-oxobutyl)-2-cyclohexen-1-ones (1) in the presence of a combination of a Lewis acid and a 1,2-diol was studied. The results suggest several factors that influence 6-membered ring formation, including two types of intramolecular aldol reaction and intramolecular 1,4-addition, due to the C3-substituent, Lewis acid, and the presence of diol. In this stu...

2015
Mayra Beatriz Gómez-Patiño Diana Yaremy Gutiérrez-Salgado Edgar García-Hernández Juan Vicente Mendez-Mendez J. Alberto Andraca Adame José Campos-Terán Daniel Arrieta-Baez

Citation: Gómez-Patiño MB, Gutiérrez-Salgado DY, García-Hernández E, Mendez-Mendez JV, Andraca Adame JA, Campos-Terán J and Arrieta-Baez D (2015) Polymerization of 10,16-Dihydroxyhexadecanoic Acid, Main Monomer of Tomato Cuticle, Using the Lewis Acidic Ionic Liquid Choline Chloride·2ZnCl2. Front. Mater. 2:67. doi: 10.3389/fmats.2015.00067 Polymerization of 10,16-Dihydroxyhexadecanoic Acid, Main...

Journal: :Chemical communications 2015
Wen-Yang Gao Kunyue Leng Lindsay Cash Matthew Chrzanowski Chavis A Stackhouse Yinyong Sun Shengqian Ma

A series of prototypal metal-organic frameworks (MOFs) consisting of polyhedral cages with accessible Lewis-acid sites, have been systematically investigated for Friedländer annulation reaction, a straightforward approach to synthesizing quinoline and its derivatives. Amongst them MMCF-2 demonstrates significantly enhanced catalytic activity compared with the benchmark MOFs, HKUST-1 and MOF-505...

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