A General and Regioselective Synthesis of Cyclopentenone Derivatives through Nickel(0)-Mediated [3 + 2] Cyclization of Alkenyl Fischer Carbene Complexes and Internal Alkynes
作者:José Barluenga、Pablo Barrio、Lorena Riesgo、Luis. A. López、Miguel Tomás
DOI:10.1021/ja075106+
日期:2007.11.1
2-cyclopentenone derivatives 3-6 are synthesized by the nickel(0)-mediated [3 + 2] cyclizationreaction of chromium alkenyl(methoxy)carbenecomplexes1 and internal alkynes2. The reaction takes place with complete regioselectivity with both unactivated alkynes and activated alkynes (electron-withdrawing and electron-donating substituted alkynes). Representative cycloadducts containing boron and tin
Nickel-Catalyzed Formation of Cyclopentenone Derivatives via the Unique Cycloaddition of α,β-Unsaturated Phenyl Esters with Alkynes
作者:Masato Ohashi、Tomoaki Taniguchi、Sensuke Ogoshi
DOI:10.1021/ja2059999
日期:2011.9.28
Oxygen-containing organic compounds, such as ethers, carboxylates, and carbamates, have recently received increasing attention because of their newly discovered applications as electrophiles in cross-coupling reactions via transition metal-catalyzed C-O bond activation. However, no cycloaddition reaction involving their C-O bond activation has been demonstrated thus far. The present study developed a Ni(O)-catalyzed unique [3+2] cycloaddition reaction of alpha,beta-unsaturated phenyl esters with alkynes in (PrOH)-Pr-i to yield cydopentenone derivatives.