Mechanistic pathways for ketene dimerization

1975 ◽  
Vol 40 (3) ◽  
pp. 207-219 ◽  
Author(s):  
Karl Jug ◽  
James Chickos
Keyword(s):  
Ketene Dimerization

Theoretical studies on the reaction mechanism of ketene dimerization reactions

1988 ◽  
Vol 167 (3-4) ◽  
pp. 349-358 ◽  
Author(s):  
Xiaoyuan (X.Y.Fu) Fu ◽  
Decai Fang ◽  
Yanbo Ding
Keyword(s):  
Reaction Mechanism ◽  
Theoretical Studies ◽  
Ketene Dimerization

Ring opening of cyclobutene-1,2-dione and 3-trimethylsilylcyclobutene-1,2-dione. Dimerization/decarbonylation of a bisketene to a ketenylbutenolide

1999 ◽  
Vol 77 (5-6) ◽  
pp. 802-805 ◽  
Author(s):  
Annette D Allen ◽  
Thomas T Tidwell
Keyword(s):  
Ring Opening ◽  
H Nmr ◽  
First Time ◽  
Hydrolysis Of ◽  
Ketene Dimerization

Hydrolysis of 3-trimethylsilyl-4,4-dichlorocyclobut-2-ene-1-one (4) in H2SO4 gave small amounts of cyclobutene-1,2-dione (2a) and 3-trimethylsilylcyclobutene-1,2-dione (2d). Photolysis of 2a gave evidence for the formation of the bisketene (CH=C=O2) (1a) in solution for the first time, as identified by the IR band at 2120 cm-1 and the 1H NMR signal at δ 3.20. Thermolysis of 2d gave evidence for the intermediacy of O=C=CHC(SiMe3)=C=O (1d), with an 1H NMR signal at δ 3.43, and the isolation of the unusual ketenyl lactone 6, which could arise by formation of an unsymmetrical [2+2] ketene dimer from 1d, followed by rearrangement and decarbonylation.Key words: bisketenes, cyclobutenediones, ketene dimerization.

Theoretical Comparison of Ketene Dimerization in the Gas and Liquid Phase

2008 ◽  
Vol 112 (14) ◽  
pp. 3192-3200 ◽  
Author(s):  
Giovanni Morales ◽  
Ramiro Martínez ◽  
Tom Ziegler
Keyword(s):  
Liquid Phase ◽  
Theoretical Comparison ◽  
Ketene Dimerization

scholarly journals Stereoelectronic Features of a Complex Ketene Dimerization Reaction

Molecules ◽  
2021 ◽  
Vol 27 (1) ◽  
pp. 66
Author(s):  
Robert D. Barrows ◽  
Mark J. Dresel ◽  
Thomas J. Emge ◽  
Paul R. Rablen ◽  
Spencer Knapp
Keyword(s):  
Clinical Trials ◽  
Carboxylic Acid ◽  
Acid Anhydride ◽  
Phase 2 ◽  
Amidation Reaction ◽  
Scale Preparation ◽  
Dimerization Reaction ◽  
Dimerization Process ◽  
Phase 2 Clinical Trials ◽  
Ketene Dimerization

The amidation reaction of a tetrahydroisoquinolin-1-one-4-carboxylic acid is a key step in the multi-kilogram-scale preparation of the antimalarial drug SJ733, now in phase 2 clinical trials. In the course of investigating THIQ carboxamidations, we found that propanephosphonic acid anhydride (T3P) is an effective reagent, although the yield and byproducts vary with the nature and quantity of the base. As a control, the T3P reaction of a 3-(2-thienyl) THIQ was performed in the absence of the amine, and the products were characterized: among them are three dimeric allenes and two dimeric lactones. A nucleophile-promoted ketene dimerization process subject to subtle steric and stereoelectronic effects accounts for their formation. Two novel monomeric products, a decarboxylated isoquinolone and a purple, fused aryl ketone, were also isolated, and mechanisms for their formation from the ketene intermediate are proposed.

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