ChemInform Abstract: Tandem Ring Expansion and Insertion Reaction of Alkenic Cyclobutanols Mediated by Palladium. A Novel Approach to Bicyclo(4.3.0)nonane Systems.

ChemInform ◽  
2010 ◽  
Vol 26 (8) ◽  
pp. no-no
Author(s):  
H. NEMOTO ◽  
M. SHIRAKI ◽  
K. FUKUMOTO
Keyword(s):  
Ring Expansion ◽  
Insertion Reaction ◽  
Novel Approach

Carbodiimide insertion into sulfonimides: one-step route to azepine derivatives via a two-atom saccharin ring expansion

2017 ◽  
Vol 53 (5) ◽  
pp. 901-904 ◽  
Author(s):  
Davin Tan ◽  
Tomislav Friščić
Keyword(s):  
Ring Expansion ◽  
Insertion Reaction ◽  
Direct Expansion ◽  
One Step

A novel carbodiimide insertion reaction enables a one-step, two-atom expansion of cyclic and linear sulfonimides, including the first direct expansion of saccharin into thiadiazepines.

The Reaction of 2-Hydro-2-oxo-5,6-benzo-l,3,2λ4-dioxaphosphorin-4-one with Imines and Carbonyl Compounds; Unusual Formation and First X-Ray Crystal Structure Determination of a Benzodioxaphosphepinone Ring System

1996 ◽  
Vol 51 (10) ◽  
pp. 1501-1510 ◽  
Author(s):  
Thomas Kaukorat ◽  
Ion Neda ◽  
Holger Thönnessen ◽  
Peter G. Jones ◽  
Reinhard Schmutzler
Keyword(s):  
Crystal Structure ◽  
Oxygen Atom ◽  
Structure Determination ◽  
Ring Expansion ◽  
Ring System ◽  
Crystal Structure Determination ◽  
Insertion Reaction ◽  
X Ray ◽  
Ir Spectroscopic

On treatment of 2-hydro-2-oxo-5,6-benzo-1,3,2λ4-dioxaphosphorin-4-one (1) with the inline trimers trim ethyl- and tribenzyltriazine and the (monomeric) methylene-tert-butylimine, an insertion reaction of the imine molecule into the P-H bond of 1 took place, forming com pounds 2 -4 . Similar results were obtained when 1 was allowed to react with aldimines, asymmetric at carbon, leading to 5-7 . The diastereotopic properties of 5 - 7 were observed by 1H NMR spectroscopy. NMR and IR spectroscopic investigations on 5 - 7 indicated > C = O···H-N < interactions. Upon reaction of 1 with hexafluoroacetone, trifluoroacetophenone or phenyltrifluoromethylketimine, the derivatives 8 -1 0 , involving a P-O-C fragment, were obtained. The formation of the isomeric “alcohol form ”, bearing a P-C-OH fragment, could not be proved. In the reaction of 1 with various o-quinones. one of the oxygen atom s of the quinone was found to be bonded to phosphorus, whereas the hydrogen atom was found to migrate to the second oxygen atom . Upon reaction of 1 with chloral, an unusual ring expansion took place with formation of the benzodioxaphosphepinone (14). The reaction of 1 with other aldehydes could not be realized. In the reaction of 14 with triethylamine, the ammonium salt 15 was formed. For the first time, an X-ray crystal structure determination of a dioxaphosphepinone ring system was conducted; in 15 the seven-membered ring displays a pseudo tub conformation.

Stereoselective Ring Expansion via Bicyclooxonium Ion. A Novel Approach to Oxocanes

2002 ◽  
Vol 4 (5) ◽  
pp. 675-678 ◽  
Author(s):  
Yasuharu Sakamoto ◽  
Kyoko Tamegai ◽  
Tadashi Nakata
Keyword(s):  
Ring Expansion ◽  
Novel Approach
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