نتایج جستجو برای: carbonyl cyanide 3

تعداد نتایج: 1825971  

Journal: :Chemical communications 2012
Depeng Zhao Lijuan Mao Linqing Wang Dongxu Yang Rui Wang

The catalytic asymmetric phospha-Michael reaction of dialkyl phosphine oxides with β,β-disubstituted α,β-unsaturated carbonyl compounds was achieved. The products bearing tetrasubstituted carbon stereocenters were obtained in high yields with excellent enantioselectivities (up to >99% ee).

Journal: :Organic & biomolecular chemistry 2014
Wei Lu Yang Li Chao Wang Dong Xue Jian-Gang Chen Jianliang Xiao

The first examples of a Pd-catalyzed carbonylation of aryl boronic acids with sp(3) carbon partners are presented. Various boronic acids were shown to react with 1,3-diesters and 1,3-diketones to afford structurally unique carbonyl compounds. By employing 2-substituted 1,3-diesters, synthetically-challenging quaternary carbon centres were accessed. In total, 42 examples of aryl carbonyl compoun...

2011
Anatolii N. Vereshchagin Michail N. Elinson Nikita O. Stepanov Gennady I. Nikishin

THE NEW TYPE OF THE CHEMICAL CASCADE REACTION WAS FOUND formation of cyclopropanes from carbonyl compounds and CH acid by the only bromine direct action. The action of aqueous bromine on the carbonyl compounds and malononitrile in EtOH-H2O solutions in the presence of NaOAc results in the formation of 3-substituted 1,1,2,2-tetracyanocyclopropanes in 48-93% yields. The latter are well-known prec...

Journal: :Organic & biomolecular chemistry 2004
Mark D Keränen Peter Eilbracht

Starting from unsaturated carbonyl compounds a mild new cascade reaction involving enolboration, rhodium-catalysed hydroformylation and intramolecular aldol addition in a regio- and diastereoselective fashion leads to cyclic compounds containing highly-functionalised quaternary carbon centres.

2016
Jose R. Cabrero-Antonino Elisabetta Alberico Kathrin Junge Henrik Junge Matthias Beller

A broad range of secondary and tertiary amides has been hydrogenated to the corresponding amines under mild conditions using an in situ catalyst generated by combining [Ru(acac)3], 1,1,1tris(diphenylphosphinomethyl)ethane (Triphos) and Yb(OTf)3. The presence of the metal triflate allows to mitigate reaction conditions compared to previous reports thus improving yields and selectivities in the d...

2014
Shaozhong Ge Sophie I. Arlow Michael G. Mormino John F. Hartwig

We report the arylation and heteroarylation of α,α-difluoro-α-(trimethylsilyl)acetamides with aryl and heteroaryl bromides catalyzed by an air- and moisture-stable palladacyclic complex containing P(t-Bu)2Cy as ligand. A broad range of electronically varied aryl and heteroaryl bromides underwent this transformation to afford α-aryl-α,α-difluoroacetamides in high yields. Due to the electrophilic...

Journal: :Angewandte Chemie 2003
Ian S Young Michael A Kerr

Cycloadditions are among the most trusted of chemical transformations available to the synthetic chemist. The predictability of the transition state based on steric and electronic considerations allows for the strategic construction of complex molecular assemblies. While the Diels–Alder reaction has received the most attention, 1,3-dipolar cycloadditions have also maintained a place of prominen...

Journal: :Organic & biomolecular chemistry 2015
Haibo Peng Jin-Tao Yu Yan Jiang Jiang Cheng

A copper-catalyzed radical 1,2-aryl migration in α,α-diaryl allylic alcohols is developed, leading to β-silyl carbonyl compounds in moderate to good yields. The migration of aryls with lower aromaticity is favored. This procedure features the employment of silanes as commercially available materials.

Journal: :Chemical science 2017
Desta Doro Bume Cody Ross Pitts Fereshte Ghorbani Stefan Andrew Harry Joseph N Capilato Maxime A Siegler Thomas Lectka

The ubiquitous ketone carbonyl group generally deactivates substrates toward radical-based fluorinations, especially sites closest to it. Herein, ketones are used instead to direct aliphatic fluorination using Selectfluor, catalytic benzil, and visible light. Selective β- and γ-fluorination are demonstrated on rigid mono-, di-, tri-, and tetracyclic (steroidal) substrates employing both cyclic ...

Journal: :Chemical communications 2018
Laura McDougall Emily R Draper Jonathan D Beadle Michael Shipman Piotr Raubo Andrew G Jamieson Dave J Adams

Low molecular weight gelators that are not easily degraded by enzymes have a range of potential applications. Here, we report new Fmoc-protected dipeptides in which the amide carbonyl group has been replaced by an oxetane ring. Remarkably one of these peptidomimetics, but not the corresponding dipeptide, is an effective gelator, forming hydrogels at a concentration of 3 mg mL-1. On assembly, th...

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