Thermochemistry of silaethylene and methylsilylene from experiment and theory
作者:Seung Koo. Shin、Karl K. Irikura、J. L. Beauchamp、William A. Goddard
DOI:10.1021/ja00209a003
日期:1988.1
Utilisation de la spectrometrie de resonance cyclotronique ionique a transformee de Fourier pour l'energetique de la deprotonation du cation CH 3 SiD 2 + , ce qui permet d'obtenir les affinites protoniques des composes du titre. Chaleurs de formation etpotentield'ionisation adiabatique
利用 de la spectrometrie de resonance cyclotronique ionique a transformee de Fourier pour l'energetique de la deprotonation du cation CH 3 SiD 2 + , ce qui permet d'obtenir les affinites protoniques des composes du titre。Chaleurs de Formation etpotentiel d'ionisation adiabatique
DMSO–DCE Triggered Chemodivergent C-Methylenation of Electron-Rich Arenes: An Easy Access to Diarylmethanes
作者:Pallaba Ganjan Dalai、Swayamprava Swain、Niranjan Panda
DOI:10.1021/acs.joc.3c02612
日期:2024.2.16
diarylmethanes through a dearomatization/rearomatization process. Methyl(methylene)sulfonium ions (CH2=S+–Me) were generated by simple heating of commonly used solvents such as DMSO and DCE. These ions were subsequently trapped by electron-rich arenes and heteroarenes, resulting in the synthesis of both symmetrical and unsymmetrical diarylmethanes. This protocol was further extended to access N-methylenamides
Chemistry and structure of the CH3O2+ product of the dioxygenyl ion-methane reaction
作者:J. M. Van Doren、S. E. Barlow、C. H. DePuy、V. M. Bierbaum、I. Dotan、E. E. Ferguson
DOI:10.1021/j100403a043
日期:1986.6
Daphniphyllum alkaloids. 11. Biomimetic total synthesis of methyl homosecodaphniphyllate. Development of the tetracyclization reaction
作者:Clayton H. Heathcock、Marvin M. Hansen、Roger B. Ruggeri、John C. Kath
DOI:10.1021/jo00035a008
日期:1992.4
A biomimetic total synthesis of (+/-)-methyl homosecodaphniphyllate has been developed. The synthesis starts with a triply convergent, tandem Michael addition-enolate alkylation, wherein amide 9, enoate 7, and alkyl iodide 5 are assembled in essentially quantitative yield to obtain compounds 13, 14, and 15. The major isomer 13 is converted in three steps into a 1:1 mixture of diols 18a and 18b. These diols are subjected to a two-step process involving Swern oxidation and treatment of the resulting dialdehyde sequentially with ammonia and acetic acid; pentacyclic unsaturated amine 23 is obtained in 82% yield. Three additional functional group steps are used to convert 23 into racemic methyl homosecodaphniphyllate ((+/-)-4). The synthesis requires nine steps and proceeds in 48% overall yield from 5, 7, and 9. The tetracyclization process was shown to proceed via dialdehyde 26, tricyclic aza diene 27, and tetracyclic imine 28. An interesting and potentially useful variant of the tetracyclization procedure employs methylamine or benzylamine instead of ammonia. In this modification, the final reaction product is pentacyclic amine 29, in which the isopropenyl double bond has also been reduced. It is suggested that this reduction occurs by intramolecular hydride transfer at the stage of cationic intermediate 33.