87712-69-4Relevant academic research and scientific papers
Generation and stereoselective transformations of 3-phenylcyclopropene
Sheshenev, Andrey E.,Baird, Mark S.,Croft, Anna K.,Bolesov, Ivan G.
experimental part, p. 10036 - 10046 (2010/02/27)
A convenient and inexpensive approach to the generation of 3-phenylcyclopropenes is described. Reaction of these compounds with a range of dienophiles and dipolarophiles led to the stereoselective formation of [4+2]- and [3+2]-cycloadducts, which were exclusively exo-3-phenyl-cis-1,2-disubstituted cyclopropanes. Efficient trapping of 1-lithio-3-phenylcyclopropene with different electrophiles is also discussed. Ab initio calculations suggest that the lowest energy conformation of 3-phenylcyclopropene has the plane of the benzene ring perpendicular to the cyclopropene π-bond but with a low rotation barrier.
Decarboxylative elimination of enol triflates as a general synthesis of acetylenes.
Fleming, Ian,Ramarao, Chandrashekar
, p. 1504 - 1510 (2007/10/03)
The enol trifluoromethanesulfonates 4, 8, 12, 17 and 20 of tert-butyl beta-ketodiesters and beta-ketoesters can be hydrolysed to the corresponding carboxylic acids by dissolution in trifluoroacetic acid. The dicarboxylic acids undergo mild decarboxylative elimination to give the acetylenic acids 4 and 9 in aqueous sodium bicarbonate solution at room temperature. Similarly, the monocarboxylic acids give the terminal and mid-chain acetylenes 13, 18, 21, and 24 by refluxing in acetone with potassium carbonate. One of the substituents on the acetylenes can be methyl, primary alkyl, secondary alkyl or ethynyl, and the other can be a carboxylic acid, hydrogen or primary alkyl, but the enol trifluoromethanesulfonates could not be prepared when one of the substituents was tert-butyl, nor when both substituents on the precursor to the acetylene were secondary alkyl.
Decarboxylative elimination of enol triflates as a general synthesis of acetylenes
Fleming, Ian,Ramarao, Chandrashekar
, p. 1113 - 1114 (2007/10/03)
Decarboxylative elimination of a range of enol triflates of β-keto esters gives acetylenes.
Polylithiumorganic compounds -21. On the Deproptonation of 1- and 3-Phenylpropyne as well as Phenylallene with Butyllithium. A Reinvestigation: Three Different Monoanions but one and the same Dianion
Maercker, Adalbert,Fischenich, Jakob
, p. 10209 - 10218 (2007/10/02)
In contrast to the literature, with butyllithium only one and the same dianion - namely 7 - is formed starting with each of the three hydrocarbons 1, 4, and 6.On the other hand, upon working at low temperature in tetrahydrofuran as the solvent we were able to detect the three corresponding monoanions 9, 15, and 16, most interestingly 15 and 16 at temperatures higher then -40 deg C show rearrangement with 1,3-hydrogen shift.
Intramolecular Carbon-Hydrogen Insertions of Alkylidenecarbenes. 1. Selectivity
Gilbert, John C.,Giamalva, David H.,Weerasooriya, Upali
, p. 5251 - 5256 (2007/10/02)
Base-promoted reaction between dialkyl ketones having γ-hydrogens and dialkyl (diazomethyl)phosphonates leads to formation of cyclopentenes in modest to high yields.The relative reactivity of various types of carbon-hydrogen bonds for the process, which involves insertion by an alkylidenecarbene, has been assessed, and the result has been compared to those reported when the carbene is generated by α elimination and by 1,2-shifts.The comparison suggests that a common species, viz., an alkylidenecarbene, may be responsible for formation of the cyclopentenes obtained from (a) flash vacuum pyrolysis of alkynes and (b) decomposition of diazoethenes, whereas that derived from α elimination of terminal vinyl halides is more selective, a result consonant with production of a carbenoid.
