Synthesis of 6<i>H</i>-Dibenzo[<i>b</i>,<i>d</i>]pyran-6-ones Using the Inverse Electron Demand Diels–Alder Reaction
作者:Ian R. Pottie、Penchal Reddy Nandaluru、Wendy L. Benoit、David O. Miller、Louise N. Dawe、Graham J. Bodwell
DOI:10.1021/jo201775e
日期:2011.11.4
These dienes reacted with the enamine derived from cyclopentanone and pyrrolidine to afford the corresponding cyclopenteno-fused 6H-dibenzo[b,d]pyran-6-ones, most likely via a domino inverseelectrondemandDiels–Alder (IEDDA)/elimination/transfer hydrogenation sequence. The parent diene (EWG = CO2Me, no substituents) was reacted with a range of electron-rich dienophiles (mostly enamines) to afford
合成了一组香豆素稠合的缺电子的1,3-二烯,它们在二烯单元末端的吸电子基团(EWG)的性质不同(当EWG = CO 2 Me时),其性质和取代基的位置。这些二烯与衍生自环戊酮和吡咯烷的烯胺反应,生成相应的环戊烯稠合的6 H-二苯并[ b,d ]吡喃-6-酮,很可能是通过多米诺逆电子需求Diels-Alder(IEDDA)/消除/转移加氢顺序。使母体二烯(EWG = CO 2 Me,无取代基)与一系列富电子的亲二烯体(主要是烯胺)反应,得到相应的6 H-二苯并[ b],d ] pyran-6-ones或它们的未脱氢前体,用合适的氧化剂处理后会被芳香化。烯胺可以在反应之前合成或就地产生。报道了30种二苯并吡喃酮的合成。
Rhodium catalysts derived from a fluorinated phanephos ligand are highly active catalysts for direct asymmetric reductive amination of secondary amines
作者:Sophie H. Gilbert、Sergey Tin、José A. Fuentes、Tamara Fanjul、Matthew L. Clarke
DOI:10.1016/j.tet.2020.131863
日期:2021.1
An asymmetric hydrogenation of enamines is efficiently catalysed by rhodium complexed with a fluorinated version of the planar chiral paracyclophane-diphosphine ligand, Phanephos. This catalyst was shown to be very active, with examples operating at just 0.1 mol% of catalyst. This catalyst was then successfully adapted to Direct AsymmetricReductive Amination, leading to the formation of several tertiary
Enamines: efficient nucleophiles for the palladium-catalyzed asymmetric allylic alkylation
作者:Xiaohu Zhao、Delong Liu、Fang Xie、Wanbin Zhang
DOI:10.1016/j.tet.2008.11.003
日期:2009.1
Enamines were tested to be efficient nucleophiles for palladium-catalyzedasymmetric allylic alkylation, avoiding the use of unstablilized ketoneenolates formed by strong bases. The influence of the chiral metallocene-based ligands upon this reaction was studied in detail. It was shown that planar chirality played an important role in enantioselectivities. Meanwhile, different kinds of enamines and
The present invention provides compounds of formula I:
1
in which:
one of X and Y is a nitrogen atom substituted by a group R
6
′ and the other is a carbon atom substituted by an isoxazole group substituted on its carbon atoms by groups R
3
and R
4
;
one of R
6
and R
6
′ is hydrogen;
either all of W
1
, W
2
, W
3
and W
4
are carbon or one of W
1
, W
2
, W
3
and W
4
is nitrogen and the rest are carbon;
and R
1
and R
2
are, independently, a small group, heteroaromatic ring or a 4-7 membered cyclic amine ring; processes for making them; pharmaceutical composition containing them; their use in therapy, particularly for enhancing cognition in conditions such as Alzheimer's Disease; and methods of treatment using them.
Diels-Alder Reaction of 1,2,3-Benzotriazine with Enamine: Application to the Synthesis of Alkaloids, 2-Propylquinoline and 2-Pentylquinoline.
作者:Junko KOYAMA、Izumi TOYOKUNI、Kiyoshi TAGAHARA
DOI:10.1248/cpb.46.332
日期:——
The Diels-Alder reaction of 1, 2, 3-benzotriazine with several pyrrolidine enamines of carbonyl compounds was carried out in chloroform in the presence of zinc bromide to afford 2- or 3-mono-, or 2, 3-disubstituted quinolines. This method was applied to the synthesis of the alkaloids, 2-propylquinoline and 2-pentylquinoline.