Oxidation of furans with dimethyldioxirane. Interception of malealdehyde and related aldehydes via Wittig reactions
作者:Brian J. Adger、Collette Barrett、Joseph Brennan、Peter McGuigan、M. Anthony McKervey、Brian Tarbit
DOI:10.1039/c39930001220
日期:——
Unsaturated aldehydes including malealdehyde, generated in acetone by oxidation of furans with dimethyldioxirane, can be trapped efficiently by phosphoranes in Wittig reactions.
Metal-Free Hydrogenation of Electron-Poor Allenes and Alkenes
作者:Blanca Inés、David Palomas、Sigrid Holle、Sebastian Steinberg、Juan A. Nicasio、Manuel Alcarazo
DOI:10.1002/anie.201205348
日期:2012.12.3
The poorer, the better: A metal‐free catalytic procedure for the reduction of electron‐poor allenes and alkenes has been developed. The method employs a frustrated Lewis pair based catalyst. 1,4‐Diazabicyclo[2.2.2]octane (DABCO)/B(C6F5)3 was shown to be the best combination in optimization studies.
越差越好:已开发出一种用于减少电子贫乏的烯和烯烃的无金属催化方法。该方法使用沮丧的路易斯对基催化剂。1,4-二氮杂双环[2.2.2]辛烷(DABCO)/ B(C 6 F 5)3被证明是优化研究的最佳组合。
A New Class of Singlet Carbene Ligands
作者:Manuel Alcarazo、Rosa M. Suárez、Richard Goddard、Alois Fürstner
DOI:10.1002/chem.201001779
日期:2010.8.23
intermediates that can be described as push–pull cumulenes or singletcarbenes (see scheme). Whereas the NMR data are ambiguous, the coordination behavior shows the ready availability of a lone pair at the central C atom. The donor ability of singletcarbeneligands of this newclass exceeds that of the commonly used N‐heterocyclic carbenes (NHCs).
Photochemical reactions of chromium-alkoxycarbene complexes with stabilized ylides to produce push-pull captodative allenes
作者:Michael R. Sestrick、Michael Miller、Louis S. Hegedus
DOI:10.1021/ja00037a008
日期:1992.5
Photolysis of chromium alkoxycarbene complexes in the presence of stabilized ylides produced allenes having effect withdrawing groups on C-1 and electron donating groups on C-3. These highly reactive captodative allenes rearranged to 1,3-substituted-1,3-dienes under mildly acidic conditions and hydrolyzed to γ-ket-α,β-unsaturated esters, both in excellent yield
ORGANOPHOSPHORUS CHEMISTRY 32. THE REACTION OF VANILLIN, <i>ORTHO</i>-VANILLIN AND PIPERONAL WITH STABILIZED METHYLENETRIPHENYLPHOSPHORANES (WITTIG REAGENTS)
作者:Taghrid S. Hafez、Maged M. Henary、Mohamed Refat、H. Mahran
DOI:10.1080/10426509808045482
日期:1998.12.1
piperonal (3) reacted with ylidenetriphenylphosphoranes 4a-f in boiling toluene following the Wittig mechanism to give the ethylenes 5a-f and 7a-f. Similarly, ethylenes 8c-f were produced when orrho-vanillin (2) was allowed to react with 4c-f. The reaction of aldehyde (2) with the P-ylides 4a,b yielded the Wittig products 8a,b and 8-methoxycoumarin (10). Triphenylphosphine oxide (TPPO, 6) was isolated