Highly stereoselective formation of cis-enediones from α-diazo carbonyl compounds catalysed by [RuCl(η5-C5H5)(PPh3)2]
作者:Walter Baratta、Alessandro Del Zotto
DOI:10.1039/a706459d
日期:——
Stereoselective decomposition of the α-diazo carbonyl compounds N2CHCOR [R = Me, Prn, Pri, (CH2)10CH3] catalysed by [RuCl(η5-C5H5)(PPh3)2] (0.1 mol%) in toluene at 65 °C affords quantitatively RCOCHCHCOR carbene dimers, the cis isomers being formed in 95â97% yield; under the same experimental conditions N2CHCOEt gives diethyl maleate in a purity of greater than 99%, the highest value for a stereoselective carbeneâcarbene dimer formation reported to date.
Generation, Observation, and Free Radical Reactivity of Aliphatic Bisketenes: The Solution to a Long-Standing Problem
作者:Annette D. Allen、Michael H. Fenwick、Amir Jabri、Huzaifa Rangwala、Kazem Saidi、Thomas T. Tidwell
DOI:10.1021/ol016853t
日期:2001.12.1
Bisketenes O=C=CH(CH(2))(n)()CH=C=O (1b,c,d, n = 4, 3, 6) and (E)-O=C=CHCH=CHCH=C=O (E-13) were generated in solution by dehydrochlorination of bis(acyl chlorides) and by photochemical Wolff rearrangements and identified by their characteristic IR signals. The bisketenes react with aminoxyl radicals to give tetraaddition products for 1b and conjugate 1,6-diaddition for E-13.
[反应:参见文本]双烯酮O = C = CH(CH(CH(2))(n)()CH = C = O(1b,c,d,n = 4,3,6)和(E)-O = C = CHCH = CHCH = C = O(E-13)是通过溶液中双(酰氯)的脱氯化氢反应和光化学Wolff重排生成的,并通过其特征IR信号进行鉴定。双烯酮与氨氧基自由基反应,得到1b的四加成产物和E-13的共轭1,6-二加成。
Gold-catalyzed intramolecular diazo coupling: an efficient macrocyclization towards cyclic olefins
作者:Chenghao Zhu、Guangyang Xu、Kai Liu、Lin Qiu、Shiyong Peng、Jiangtao Sun
DOI:10.1039/c5cc04830c
日期:——
A gold-catalyzed synthesis of medium to large membered cyclic olefins has been developed.
一种利用金催化的合成中等到大环烯烃的方法已经开发出来了。
Synthesis of some medium- and large-ring cycloalk-2-ene-1,4-diones by intramolecular coupling of αω-bis-diazoketones
作者:Sunanta Kulkowit、M. Anthony McKervey
DOI:10.1039/c39780001069
日期:——
In the presence of Cu(acac)2(Hacac = acetylacetone) someαω-bis-diazoketones couple intramolecularly with loss of nitrogen giving cycloalk-2-ene-1,4-diones; the enediones can be converted into fused ring cyclopentenones by successive treatment with sodium dithionite and sodium hydroxide.