Cationic Rhodium(I)/H<sub>8</sub>-binap Complex Catalyzed [2+2+2] Cycloadditions of 1,6- and 1,7-Diynes with Carbonyl Compounds
作者:Yousuke Otake、Rie Tanaka、Ken Tanaka
DOI:10.1002/ejoc.200900185
日期:2009.6
catalyzes [2+2+2] cycloadditions of a variety of 1,6- and 1,7-diynes with both electron-deficient and electron-rich carbonyl compounds, leading to dienones in high yield under mild reaction conditions. In the reactions with acyl phosphonates, the reactivity of 1,6- and 1,7-diynes was highly dependent on their own structures. The addition of chelating diethyl oxalate effectively promoted the [2+2+2] cycloadditions
Use of Acyl Phosphonates as
a Coupling Partner for Rhodium-Catalyzed [2+2+2] Cycloaddition:
Unexpected Dependence of the Reactivity on Structures
of α,ω-Diynes
A cationic rhodium(I)-H8-BINAP complex catalyzes a [2+2+2] cycloaddition of 1,6- and 1,7-diynes with acyl phosphonates in high yields with high regioselectivity. Interestingly, the reactivity of α,Ï-diynes toward acyl phosphonates is highly dependent on their own structures.
A cationic rhodium(I)/BINAP [2,2′-bis(diphenylphosphino)-1,1′-binaphthyl] complex is capable of catalyzing the [2+2+2] cycloaddition–aromatization of 1,6-diynes with cyclicenolethers (2,3-dihydrofuran and dihydropyran) at roomtemperature to produce the corresponding aryl alkanol derivatives in good yields. In this process, a conjugated dihydrofuran showed a significantly higher reactivity than a
Synthesis of Perfluoroalkylated Benzenes and Pyridines through Cationic Rh(I)/Modified BINAP-Catalyzed Chemo- and Regioselective [2 + 2 + 2] Cycloaddition
A convenient synthesis of perfluoroalkylated benzenes and pyridines has been achieved by a cationic Rh(I)/modified BINAP-complex-catalyzed chemo- and regioselective [2 + 2 + 2] cycloaddition of alkynes with a perfluoroalkylacetylene and a perfluoroalkylnitrile.
Enantioselective Construction of Bridged Multicyclic Skeletons: Intermolecular [2+2+2] Cycloaddition/Intramolecular Diels-Alder Reaction Cascade
Bridging a gap: A cationic rhodium(I)/ligand complex catalyzes the title reaction of alkynes and amide‐linked 1,5‐dienes, leading to bridged multicyclic compounds, with high chemo‐, regio‐, and enantioselectivity (see scheme; Bn=benzyl).