Cu(I)-catalyzed reaction of diazo compounds with terminal alkynes: a direct synthesis of trisubstituted furans
作者:Mohammad Lokman Hossain、Fei Ye、Yan Zhang、Jianbo Wang
DOI:10.1016/j.tet.2014.07.086
日期:2014.9
method for the synthesis of tri-substituted furans has been developed based on Cu(I)-catalyzed reaction of terminalalkynes with β-keto α-diazoesters. This method for the synthesis of 2,3,5-trisubstituted furans is operationally simple and applicable to wide substrate scope. Moreover, this synthesis employs cheap Cu(MeCN)4PF6 as the catalyst and no additional ligand is needed. Similar reaction has also been
2,3,4- or 2,3,5-Trisubstituted Furans: Catalyst-Controlled Highly Regioselective Ring-Opening Cycloisomerization Reaction of Cyclopropenyl Ketones
作者:Shengming Ma、Junliang Zhang
DOI:10.1021/ja036616g
日期:2003.10.1
furans were highlyregioselectively formed from the cycloisomerizationreaction 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
2-(tetrahydroxybutyl)furans (4) by co-reacting with 1,3-dicarbonyl compounds such as ethyl acetoacetate (1). The key step of the reaction is the formation of a furan at the reducing end followed by the attack of the 2-OH group of the last-but-one AGU at this terminal furan. The intermediate, unstable dioxepane fragments by cleavage of the glycosidic bond. The terminal AGU is released as a substituted furan, the “new”
Catalyst-Controlled Ring-Opening Cycloisomerization Reactions of Cyclopropenyl Carboxylates for Highly Regioselective Synthesis of Different 2-Alkoxyfurans
作者:Jie Chen、Shengming Ma
DOI:10.1002/asia.201000324
日期:2010.11.2
Differently substituted 2‐alkoxyfurans (2,3,4‐ or 2,3,5‐trisubstituted furans) were highlyregioselectively synthesized by means of the ring‐opening cycloisomerization of the same cyclopropenylcarboxylates with good yields in different solvents and excellent regioselectivity by using [Cu(acac)2] (acac=acetylacetonate) or [RuCl2(PPh3)3] as the catalyst, respectively. The structures of these two different