نتایج جستجو برای: ketones

تعداد نتایج: 9200  

Journal: :Organic & biomolecular chemistry 2014
Karuppusamy Sakthivel Kannupal Srinivasan

Indium(III) triflate is found to be an effective catalyst for the benzannulation reactions of o-alkynylbenzaldehydes with enolisable aldehydes, ketones, 1,3-diketones and β-keto esters. The reactions produce naphthyl ketones through ring opening of adducts arising from the inverse electron demand Diels-Alder reactions between in situ generated isochromenylium cations and enols. The main feature...

Journal: :Organic & biomolecular chemistry 2018
Kazumasa Funabiki Ayaka Hayakawa Toshiyasu Inuzuka

A new convenient, functional group-tolerant, transition metal-free route to aryl trifluoromethyl ketones under mild conditions is described. The reaction of not only aryl Grignard reagents carrying reducible electrophilic functional groups, such as ester and cyano groups, but also electron-deficient nitrogen-containing heteroaryl Grignard reagents with methyl trifluoroacetate gives the correspo...

Journal: :Chemical communications 2015
Wei Ma Dong Xue Ting Yu Chao Wang Jianliang Xiao

The first allylic carbonylation reaction of allylic acetates with aryl boronic acids under carbon monoxide has been developed. Using Pd-PCy3 as a catalyst, a wide spectrum of allylic acetates was carbonylated in the presence of various aryl boronic acids, affording α,β-unsaturated aryl ketones in good to excellent yields. Preliminary studies indicate that carbon monoxide always inserts at the l...

2014
Louis K M Chan Darren L Poole Di Shen Mark P Healy Timothy J Donohoe

The rhodium-catalyzed methylation of ketones has been accomplished using methanol as the methylating agent and the hydrogen-borrowing method. The sequence is notable for the relatively low temperatures that are required and for the ability of the reaction system to form α-branched products with ease. Doubly alkylated ketones can be prepared from methyl ketones and two different alcohols by usin...

Journal: :journal of sciences islamic republic of iran 0

in an environmentally benign solventless system, aldehydes and ketones were readily converted to their corresponding azines with hydrazine sulfate, sodium hydroxide and alumina in high yield.

Journal: :Science-Business eXchange 2010

2005

When exposed to hypoxia, intact mice, with elevated blood ketones, live longer than mice with normal blood ketones. To evaluate a possible mechanism responsible for this phenomenon a rat brain slice preparation was used to determine if brain tissue would utilize glucose or ketones preferentially during exposure to reduced oxygen. Reducing available oxygen in the incubation medium from 95%, in s...

Journal: :Stroke 1984
J R Kirsch L G D'Alecy

When exposed to hypoxia, intact mice, with elevated blood ketones, live longer than mice with normal blood ketones. To evaluate a possible mechanism responsible for this phenomenon a rat brain slice preparation was used to determine if brain tissue would utilize glucose or ketones preferentially during exposure to reduced oxygen. Reducing available oxygen in the incubation medium from 95%, in s...

Journal: :Organic & biomolecular chemistry 2011
Qiang Kang Yugen Zhang

Aza-Michael addition of amines, including aromatic and aliphatic amines, with α, β-unsaturated ketones was realized employing N-Heterocyclic Carbene (NHC) as organocatalyst, yielding β-amino ketones with up to 98% yield.

Journal: :Chemical communications 2012
Shohei Aoki Shunsuke Kotani Masaharu Sugiura Makoto Nakajima

Trichlorosilyl triflate-promoted directed cross-aldol reaction between ketones in the presence of a chiral phosphine oxide as an organocatalyst is described. This is the first enantioselective cross-aldol reaction between simple ketones with good enantioselectivity.

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