Copper-Mediated N-Alkynylation of Carbamates, Ureas, and Sulfonamides. A General Method for the Synthesis of Ynamides
作者:Joshua R. Dunetz、Rick L. Danheiser
DOI:10.1021/ol035647d
日期:2003.10.1
[reaction: see text] A general amination strategy for the N-alkynylation of carbamates, sulfonamides, and chiral oxazolidinones and imidazolidinones is described. A variety of substituted ynamides are available by deprotonation of amides with KHMDS followed by reaction with CuI and an alkynyl bromide.
[反应:见正文] 描述了氨基甲酸酯、磺酰胺、手性恶唑烷酮和咪唑烷酮的 N-炔基化的一般胺化策略。通过用 KHMDS 对酰胺进行去质子化,然后与 CuI 和炔基溴反应,可以获得各种取代的炔酰胺。
Synthesis of Highly Substituted Indolines and Indoles via Intramolecular [4 + 2] Cycloaddition of Ynamides and Conjugated Enynes
作者:Joshua R. Dunetz、Rick L. Danheiser
DOI:10.1021/ja051180l
日期:2005.4.1
Ynamides react with conjugated enynes in intramolecular [4 + 2] cycloadditions to afford substituted indolines that undergo oxidation with o-chloranil to furnish the corresponding indoles. The cycloaddition substrates are easily assembled from derivatives of 3-butynylamine by Sonogashira coupling with alkenyl halides followed by copper-catalyzed N-alkynylation with acetylenic bromides. Diynamides participate
Alkylene chains with up to 40 methylene groups were employed. The two terminal acetylene functions were introduced prior to the oligoyne elongation by twofold introduction of additional C2-acetylene or C4-butadiyne building blocks. The final step was the intramolecular acetylene coupling upon which very large macrocycles with up to 62 ring members containing segregated sp-, sp2- and sp3-segments were formed
A Convenient Negishi Protocol for the Synthesis of Glycosylated Oligo(ethynylene)s
作者:Tobias N. Hoheisel、Holger Frauenrath
DOI:10.1021/ol801807a
日期:2008.10.16
A convenient and efficient sp-sp carbon heterocoupling protocol based on the Negishi reaction was developed, in which the required zinc diacetylide was generated from 1,4-bis(trimethylsilyl)butadiyne in situ and reacted with a bromoacetylene in apolar solvent mixtures. The method has been applied to the synthesis of unsymmetric glycosylated and symmetric diglycosylated oligo(ethynylene)s up to the