نتایج جستجو برای: ketene

تعداد نتایج: 674  

Journal: :The Journal of chemical physics 2004
Johanna L Miller Laura R McCunn Maria J Krisch Laurie J Butler Jinian Shu

This work is a study of the competition between the two unimolecular reaction channels available to the vinoxy radical (CH(2)CHO), C-H fission to form H+ketene, and isomerization to the acetyl radical (CH(3)CO) followed by C-C fission to form CH(3) + CO. Chloroacetaldehyde (CH(2)ClCHO) was used as a photolytic precursor to the vinoxy radical in its ground state; photodissociation of chloroaceta...

Journal: :Tetrahedron letters 2011
Yu-Pu Wang Rick L Danheiser

The first synthesis of 2-iodoynamides is described as well as the first [2+2] cycloadditions of ketene with iodo alkynes.

Journal: :Berichte der deutschen chemischen Gesellschaft (A and B Series) 1920

Journal: :The Astrophysical Journal 2021

Abstract It is speculated that there might be some linkage between interstellar aldehydes and their corresponding alcohols. Here an observational study astrochemical modeling are coupled together to illustrate the connection them. The ALMA cycle 4 data of a hot molecular core, G10.47+0.03, utilized for this study. Various (acetaldehyde, propanal, glycolaldehyde), alcohols (methanol ethylene gly...

Journal: :Chemical communications 2014
Xichen Xu John S Leszczynski Savannah M Mason Peter Y Zavalij Michael P Doyle

In a reaction that proceeds under mild conditions with remarkable functional group tolerance, structurally diverse 3-amino-2-cyclopentenones bearing a quaternary carbon at the 4-position have been synthesized through a formal [3+2]-cycloaddition reaction of silylated ketene imines (SKIs) and enoldiazoaceates by dirhodium catalysis.

Journal: :Journal of the American Chemical Society 2004
Julius T Su Richmond Sarpong Brian M Stoltz William A Goddard

The substrate scope for a ketene-assisted Cope (tandem Wolff-Cope) reaction is elucidated from first-principles quantum mechanics. An alternate pathway (trans) leading to an undesired and unstable product lies perilously close ( approximately 2.5 kcal/mol) to the primary (cis) reaction pathway; this near-degeneracy arises from preferential ketene stabilization of a radicaloid trans transition s...

Journal: :Journal of the American Chemical Society 2007
Scott E Denmark Tyler W Wilson Matthew T Burk John R Heemstra

Silyl ketene imines derived from a variety of alpha-branched nitriles have been developed as highly useful reagents for the construction of quaternary stereogenic centers via the aldol addition reaction. In the presence of SiCl4 and the catalytic action of chiral phosphoramide (R,R)-5, silyl ketene imines undergo extremely rapid and high yielding addition to a wide variety of aromatic aldehydes...

Journal: :Angewandte Chemie 2022

Heterogeneous Catalysis. In their Communication (e202207777), Patrick Hemberger et al. employed PEPICO spectroscopy to identify ketene and methylketene intermediates in methyl acetate conversion over the HZSM-5 zeolite.

Journal: :Synlett 2014

Journal: :Proceedings of the National Academy of Sciences of the United States of America 2005
G K Surya Prakash Chulsung Bae Golam Rasul George A Olah

Electrophilic triethylsilylation of diphenylketene leads to exclusive C-silylation giving the diphenyl(triethylsilyl)acetyl cation in the solution phase even though density functional theory calculations at the B3LYP/6-311+G* level indicate that the O-silylation of diphenylketene is preferred over C-silylation by 5.4 kcal/mol in the gas phase. On the other hand, in the case of the parent ketene...

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