Reductive cyclisation of allenic ketones. A new approach to functionalised five-membered rings.
作者:Gerald Pattenden、Graeme M. Robertson
DOI:10.1016/s0040-4039(00)85971-7
日期:1983.1
Electrolysis of a series of terminal allenic ketones, (4), (6), and (13) is shown to result in reductive cyclisation, through the -mode, producing five-membered rings, (5), (7), and (14) incorporating a bridgehead hydroxyl group.
Synthesis of spiroisoindolinones by palladium-catalyzed heterocyclization of 2-iodobenzoyl chloride with ketimines
作者:Chan Sik Cho、Xue Wu、Li Hong Jiang、Sang Chul Shim、Hong Rak Kim
DOI:10.1002/jhet.5570360147
日期:1999.1
2-Iodobenzoyl chloride reacts with ketimines in acetonitrile at 100° undercarbonmonoxidepressure in the presence of a catalytic amount of a palladium catalyst together with triethylamine to afford the corresponding spiroisoindolinones in high yields.
Formation of 1,2,3,4-tetrahydro-2-pyridones by aza-annulation of imines with acrylate derivatives
作者:K. Paulvannan、John R. Stille
DOI:10.1021/jo00046a011
日期:1992.9
The aza-annulation of imines with activated acrylate derivatives was studied as a means of preparing the corresponding 1,2,3,4-tetrahydro-2-pyridones. Through the use of reagents known to facilitate the formation of amide bonds from carboxylic acids, several methods of activating the acrylate species were compared. The acrylate derivatives studied were acryloyl chloride and acrylic anhydride as well as acrylic acid activated by reaction with EtO2CCl, (PhO)2P(O)N3, or MCPI. Optimum annulation was obtained with imines derived from cyclohexanone to produce octahydro-2-quinolone products. The N-isobutylimine prepared from cyclopentanone also produced selective ring annulation to efficiently produce the corresponding bicyclic product, but the reaction with the imine of n-butanal produced lower yields of cyclic product. Ring formation was relatively unaffected by substituents at the a-position of the acrylate derivative, demonstrated by the use of methacrylate, but beta-substituents hindered the annulation process and, in turn, increased the amounts of byproduct resulting from only N-acylation of the imine. Increasing the steric bulk of the imine alkyl substituent produced the opposite effect; the relative amount of N-acylation compared to complete aza-annulation was diminished as the size of the substituent was increased. Mechanistic features of the reaction are discussed in terms of product distribution and competition experiments.
PATTENDEN, G.;ROBERTSON, G. M., TETRAHEDRON, 1985, 41, N 19, 4001-4011
作者:PATTENDEN, G.、ROBERTSON, G. M.
DOI:——
日期:——
Spirocyclic Diaminocarbenes: Synthesis, Coordination Chemistry, and Investigation of Their Dimerization Behavior
作者:F. Ekkehardt Hahn、Martin Paas、Duc Le Van、Roland Fröhlich
DOI:10.1002/chem.200500306
日期:2005.8.19
Nonaromatic, "saturated", spirocyclic N-heterocyclic diaminocarbenes 11 can be obtained from spirocyclic imidazolidin-2-thiones 10 by reductive desulfurization with potassium. The unsymmetrically N,N'-substituted spirocyclic imidazolidin-2-thiones were obtained by reaction of ketimines 9 with lithium N-butyl-N-lithiomethyldithiocarbamate (6). 13C NMR spectroscopy revealed that the unsymmetrically N