Gold-catalyzed homo- and cross-annulation of alkynyl carboxylic acids: a facile access to substituted 4-hydroxy 2<i>H</i>-pyrones and total synthesis of pseudopyronine A
demonstrated. The reaction tolerates various substituted alkynyl carboxylic acids and moderate to good yields of α-pyrone scaffolds have been observed. Later, a gram-scale reaction of the acid and the totalsynthesis of the natural product pseudopyronine A have been carried out successfully.
已经证明了 Au( I ) 催化的炔基羧酸的均环化和交叉环化反应,提供了 3,6-二取代的 4-羟基 2 H-吡喃酮。该反应耐受各种取代的炔基羧酸,并观察到中等至良好产率的α-吡喃酮支架。随后,该酸的克级反应和天然产物假吡咯啉A的全合成已成功进行。
Selective Mono- and Dialkynylation of 1-Fluoro-2,2-diiodovinylarenes Using Pd-Catalyzed Decarboxylative Coupling Reactions
作者:Aravindan Jayaraman、Sunwoo Lee
DOI:10.1021/acs.orglett.9b02907
日期:2019.10.4
Palladium-catalyzed decarboxylative coupling reactions using alkynoic acids and 1-fluoro-2,2-diiodovinylarenes provide mono- and dialkynylfluoroalkenes with high selectivity. When the reaction was conducted using DBU/DMSO, the hydrodeiodinated monoalkynylfluoroalkene product was formed, whereas performing the reaction using Et3N/THF gave the dialkynylfluoroalkene product. Both reaction conditions gave high yields of
使用炔酸和1-氟-2,2-二碘乙烯基芳烃的钯催化的脱羧偶联反应可提供高选择性的单-和二-炔基氟烯烃。当使用DBU / DMSO进行反应时,形成了加氢碘化的单炔基氟代烯烃产物,而使用Et 3 N / THF进行反应则得到了二炔基氟代烯烃产物。两种反应条件均产生了高产率的带有氟原子的所需烯炔和乙炔产物。
Rhodium-Catalyzed Enantioselective Decarboxylative Alkynylation of Allenes with Arylpropiolic Acids
作者:Christian P. Grugel、Bernhard Breit
DOI:10.1021/acs.orglett.7b04035
日期:2018.2.16
A rhodium-catalyzed chemo-, regio-, and enantioselective intermolecular decarboxylative alkynylation of terminal allenes with arylpropiolic acids is reported. Employing a Rh(I)/(R)-Tol-BINAP catalytic system, branched allylic 1,4-enynes were obtained under mild conditions. The overall utility of this protocol is exemplified by a broad functional group compatibility.