Reaction of Arylglyoxals with Electron-Rich Benzenes and π-Excessive Heterocycles. Facile Synthesis of Heteroaryl α-Acyloins
The reaction of arylglyoxals and their hydrates with electron-rich benzenes and π-excessive heterocycles, if conducted in the absence of catalysts, affords α-benzoins.
Ivonin, Sergey P.,Lapandin, Andrey V.,Anishchenko, Andrey A.,Shtamburg, Vasilii G.
p. 451 - 461
(2007/10/03)
Reductive Coupling of Benzoyl Cyanide and Carbonyl Compounds by Aqueous Ti(III) Ions. A New Convenient and Selective Access to the Less Stable Mixed Benzoins
The reactive species formed by the Ti(III) ion reduction of benzoyl cyanide (1) adds to the C-atom of carbonyl compounds 2 under simple experimental conditions.The intermediate 1,2-diols 3 are smoothly converted, without isolation, into the less thermodynamically stable mixed benzoins 4, which are not accessible by the classical benzoin condensation.The possible mechanisms involved in the reaction are discussed.
Clerici, Angelo,Porta, Ombretta
p. 2889 - 2893
(2007/10/02)
Cyclisation of benzils
-
Cremlyn,Swinbourne,Shode,Lynch
p. 117 - 121
(2007/10/02)
66. Synthese und Reaktionen des 5--2,2-dimethyl-4-phenyl-3-oxazolins
Synthesis and Reactions of 5--2,2-dimethyl-4-phenyl-3-oxazoline.The title compound 8 has been synthesized in a one-pot reaction of 4'-(dimethylamino)benzoin (4) with 2-propanone and NH3.The preparation of the intermediate 4 from 3 is the first example of an acid-catalyzed transformation of the stable benzoin 3 into the corresponding less stable benzoin 4.Structures and yields of various by-products occuring under different reaction conditions during the synthesis of 8 from 4 are given.The O-atom of the 3-oxazoline ring in 8 could be replaced by S from P2S5 yielding the 3-thiazoline 14.Separation of the enantiomers of the racemate 8 could only be performed by transforming them into the trimethylanilinium salts 8b and 8c of (-)- and (+)-10-camphorsulfonic acid, respectively.Solid NaOAc in boiling toluene caused the precipitation of the 10-camphorsulfonic acids from the quaternary ammonium salts as sodium salts and the removing of the third methyl group from the quaternary ammonium salts as AcOMe to give the enantiomers (-)-(5S)-8 and (+)-(5R)-8.Their absolute configurations are deduced from an X-ray analysis of 8b.
Foricher, Joseph,Montavon, Francois,Pfoertner, Karl-Heinz,Schoenholzer, Peter
p. 592 - 599
(2007/10/02)
SOLVENT EFFECTS ON THE ELECTRONIC STRUCTURE OF BIS(4-DIMETHYLAMINODITHIOBENZYL) NICKEL II(4-DMAB)> FROM UV-VIS AND EPR SPECTRA
The UV-VIS and EPR spectra of solutions of NiII(4-DMAB) in 10 solvents with donor number (DN) from 0.1 to 38.8 have been recorded.The changes in the spectra are explained in terms of a change in symmetry of the NiII(4-DMAB) complex on increase in donor number of the solvent.The symmetry change is from square planar to rhombic bipyramidal with corresponding change in electronic configuration of the nickel ion from d2z2 to d1z2, d1x2-y2.Light was observed to accelerate this structural change.
Graczyk, A.,Bialkowska, E.,Konarzewski, A.
p. 2715 - 2720
(2007/10/02)
More Articles about upstream products of 33458-29-6