Ma Shengming, Zhang Junliang
State Key Laboratory of Organometallic Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, 354 Fenglin Lu, Shanghai 200032, P R China.
J Am Chem Soc. 2003 Oct 15;125(41):12386-7. doi: 10.1021/ja036616g.
2,3,4- or 2,3,5-trisubstituted furans were highly regioselectively formed from the cycloisomerization reaction of the same starting cyclopropenes 1 via the subtle choice of the transition metal halides. Under the catalysis of 5 mol % PdCl2(CH3CN)2, 2,3,5-trisubstituted furans 2 were given in 50-88% yields with 95-99% regioselectivities, while 2,3,4-trisubstituted furans 3 were formed in 78-96% yields with 99% regioselectivities under the catalysis of 5 mol % CuI.
通过对过渡金属卤化物的巧妙选择，由相同的起始环丙烯1经环异构化反应可高度区域选择性地生成2,3,4 - 或2,3,5 - 三取代呋喃。在5 mol% PdCl2(CH3CN)2催化下，可得到产率为50 - 88%、区域选择性为95 - 99%的2,3,5 - 三取代呋喃2；而在5 mol% CuI催化下，可生成产率为78 - 96%、区域选择性为99%的2,3,4 - 三取代呋喃3。
