Pyrrolo[2,3-d]pyrimidine synthesis through activation of N-benzyl groups by distal amides
作者:Laurent El Kaïm、Laurence Grimaud、Simon Wagschal
DOI:10.1039/c3ob41477a
日期:——
A new activation mode of CH2–benzylamino groups has been observed during the preparation of pyrrolopyrimidines from Ugi–Smiles adducts of hydroxypyrimidines. The cyclization proceeds via a formal deprotonation of the N-benzyl group followed by trapping of the resulting anion by the alkyne moiety. The key role of the vicinal amide function during the process was pointed out.
Palladium catalyzed ring opening of furans as a route to α,β-unsaturated aldehydes
作者:Laurent El Kaïm、Laurence Grimaud、Simon Wagschal
DOI:10.1039/c0cc04164e
日期:——
Furans may be ring opened via pallado-catalyzed reactionsleading to alpha,beta-unsaturated aldehydes and ketones tethered to indole and isoquinoline moieties. Besides their synthetic interest, these fragmentations bring interesting elements into the discussion around the reaction mechanisms involved in palladium C-H activations of electron-rich heterocycles.
Three kinds of pyridopyrimidines were synthesized from appropriate pyrimidine derivatives. Cross-coupling of 4-amino-5-iodopyrimidines with α, β-unsaturated carboxylic esters followed by ring-closure afforded pyrido [2, 3-d] pyrimidines. Ammonolysis of 4-ethoxycarbonyl-5-phenylethynyl-and 5-ethoxycarbonyl-4-phenyl-ethynyl-pyrimidines which were obtained by cross-coupling of the corresponding halopyrimidines with phenylacetylene, gave pyrido [3, 4-d]-and pyrido [4, 3-d]-pyrimidines, respectively.
Palladium-Catalyzed Ring Opening of Aminocyclopropyl Ugi Adducts
作者:Laurent El Kaïm、Laurence Grimaud、Aurélie Dos Santos、Romain Ramozzi
DOI:10.1055/s-0031-1290312
日期:2012.2
The ring opening of aminocyclopropanes triggered by activation with an intramolecular arylpalladium(II) iodide complex is an interesting strategy for the synthesis of nitrogen heterocycles and a valuable Ugi postcondensation-type transformation. Six- and seven-membered-ring cyclic enamines may be obtained. aminocyclopropanes - ring opening - palladium - Ugi - Ugi-Smiles
作者:Laurent El Kaïm、Laurence Grimaud、Simon Wagschal
DOI:10.1021/jo100759b
日期:2010.8.6
Herein, we present a newroute to highly substituted pyrrolo[2,3-d]pyrimidines featuring a Ugi−Smiles/Sonogashira cascade followed by an efficient base-catalyzed intramolecular cyclization. When formaldehyde is chosen as input in the Ugi−Smiles step, aromatic fused systems are eventually obtained through the isomerization of an exo-alkylidene intermediate.
在这里,我们提出了一种新的途径,以具有Ugi-Smiles / Sonogashira级联的高取代的吡咯并[2,3- d ]嘧啶为代表,随后进行了有效的碱催化分子内环化反应。当在Ugi-Smiles步骤中选择甲醛作为输入时,最终通过外亚烷基中间体的异构化获得芳族稠合体系。