Commercially available liquid enol ethers and acetates as gaseous alkyne equivalents in cationic Rh(I)/BINAP-catalyzed chemo- and regioselective formal cross-alkyne cyclotrimerizations
作者:Hiromi Hara、Masao Hirano、Ken Tanaka
DOI:10.1016/j.tet.2009.02.047
日期:2009.6
A cationic rhodium(I)/BINAP complex catalyzes partial intramolecular [2+2+2] cycloadditions of 1,6- and 1,7-diynes with enol ethers or a ketene acetal giving substituted benzenes in good yields. The same catalyst also catalyzes complete intermolecular [2+2+2] cycloadditions of two different monoynes with enol acetates giving tri- and tetrasubstituted benzenes in good yields with complete regioselectivity
阳离子铑(I)/ BINAP络合物可催化1,6-和1,7-二炔与烯醇醚或乙烯酮缩醛的部分分子内[2 + 2 + 2]环加成反应,从而以高收率得到取代的苯。相同的催化剂还催化两种不同的单炔与烯醇乙酸酯的完全分子间[2 + 2 + 2]环加成反应,从而以良好的收率和完全的区域选择性得到三和四取代的苯。在当前的铑催化的正式跨炔烃环三聚反应中,可商购的液体烯醇醚和乙酸酯可用作气态炔烃的通用等同物。