Rh(III)-催化的 2-重氮-1,3-二酮与 1,3-二羰基化合物的级联亲核加成/环化以获得 6,7-二氢苯并呋喃-4(5 H )-酮
摘要:
2-重氮-1,3-二酮与1,3-二羰基化合物(例如1,3-二酮和β-酮酯)的Rh(III)催化级联亲核加成/分子内环化得到6, 7-dihydrobenzofuran-4(5 H )-ones 的产率高达 91%。值得注意的是,在优化的反应条件下,广泛的底物和官能团具有良好的耐受性,以中等至优异的产率得到所需产物,同时释放出 N 2和 H 2 O 作为副产物。此外,所描述的方法是可扩展的,适用于后期功能化。
Here, we have reported synthesis of 3,4-dicarbonyl substituted poly-functionalized furan derivatives via direct functionalization of α,β-unsaturated carbonyl compounds through conjugate addition initiated dominoreactions using CuO nanoparticles as a reusable catalyst in aqueous ethanol.
Photocatalytic synthesis of tetra-substituted furans promoted by carbon dioxide
作者:Ya-Ming Tian、Huaiju Wang、Ritu、Burkhard König
DOI:10.1039/d1sc06403g
日期:——
compounds in carbon dioxide (CO2) atmosphere under mild conditions. It was found that CO2 could be incorporated at the diketone enolic OH position, which was key to enabling the cleavage of a C–O bond during the rearrangement of a cyclopropaneintermediate. This method allows for the same-pot construction of two isomers of the high-value tetra-substituted furan scaffold. The synthetic scope and preliminary
Piano-Stool Rhodium Enalcarbenoids: Application to Catalyst-Controlled Metal-Templated Annulations of Diazoenals and 1,3-Dicarbonyls
作者:Bapurao Sudam Lad、Sreenivas Katukojvala
DOI:10.1021/acscatal.8b03865
日期:2018.12.7
An electrophilic piano-stool rhodium(III)-enalcarbenoid resulted from the reaction of diazoenal with the cationic Cp*Rh-III in the presence of a 1,3-diketone. The synthetic utility of these transient carbenoids has been demonstrated in the metal-templated [3 + 2] annulation of diazoenals and 1,3-dicarbonyls, thus leading to the enal-functionalized tetrasubstituted furans. The significance of the piano-stool enalcarbenoids has been further exemplified by the mechanistically distinct, complementary Lewis acid templated [2 + 3] annulation of diazoenals and 1,3-dicarbonyls, resulting in the trisubstituted furanyl-enones and acrylates. Mechanistic investigations revealed that these annulations proceed through catalyst-dependent chemoselective activation of diazoenal by the in situ formed metal diketonates. These methodologies gave access to core structures of indeno[1,2-b]furans, tetracyclic OLED, and a pan-AKT inhibitor.
Manganese Dioxide-Mediated Oxidative Coupling of 1,3-Dicarbonyl Compounds with α,β-Unsaturated Ketones: Direct Access to 3,4-Dicarbonyl Substituted Furans
AbstractAn efficient manganese dioxide‐mediated and highly selective oxidative CH/CH functionalization of 1,3‐dicarbonyl compounds with α,β‐unsaturated ketones for the construction of tetrasubstituted furans in one step has been demonstrated. This catalytic system converts two CH bonds and CO bonds to CC and CO bonds. This reaction provides a facile and regio‐defined method for the synthesis of 3,4‐dicarbonyl substituted furans.magnified image