نتایج جستجو برای: lewis acid

تعداد نتایج: 761908  

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...

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...

2002
Keiji Maruoka

The chemistry of bidentate Lewis acids belongs to an unexplored field of science, and so far has been only poorly studied. This paper illustrates the design of several bidentate Al and Ti Lewis acids, and their successful application to selective organic synthesis, particularly to asymmetric synthesis. For example, a new, chiral bidentate Ti(IV) complex is successfully designed by adding commer...

Journal: :Green Chemistry 2022

The catalytic activity was enhanced by the introduction of C18PA on support Ru/Nb 2 O 5 catalyst. addition more Lewis acid sites activated aromatic ring in phenol and promoted formation cyclohexanol.

نمودار تعداد نتایج جستجو در هر سال

با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید