Control of regioselectivity in the Diels–Alder reactions of alkyl-substituted 1,4-benzoquinones by β-cyclodextrin and its derivatives
作者:Wen-Sheng Chung、Ju-Ying Wang
DOI:10.1039/c39950000971
日期:——
The Diels-Alder reactions of benzoquinones 1-3with penta-1, 3-diene 4 and isoprene 5 are studied in aqueous cyclodextrin solutions, where highly enhanced ortho(6, 8 and 10) and meta(13, 15) regioselectivities are achieved.
Catalysis and regioselectivity of quinone Diels–Alder reactions
作者:James B. Hendrickson、Vishwakarma Singh
DOI:10.1039/c39830000837
日期:——
In a series of six different cycloadditions of unsymmetrical quinones and alkyl-substituted butadienes, TiCl4 afforded considerable catalysis (–78 °C) and gave regioselectivity identical with that of the thermal reaction (200 °C) and therefore complementary to that BF3 catalysis.
Regio- and Stereoselectivity in the Reductions of Cyclic Enedione Systems
作者:Chunjian Liu、D. Jean Burnell
DOI:10.1021/jo962377m
日期:1997.5.1
Reductions of cyclic enedione substrates by NaBH4 and by LiAl(O-t-Bu)(3)H very predominantly gave monoreduction products with very high regio- and stereoselectivity. The reductions involved axial delivery of the hydride. The results indicated that electronic factors were dominated by steric considerations in the transition state of the reduction, even though the seemingly more encumbered carbonyl was reduced.
Solvent-free Diels–Alder reactions catalyzed by FeCl3 on Aerosil® silica
作者:Maria C. Donatoni、Gilmar A.B. Junior、Kleber T. de Oliveira、Romulo A. Ando、Timothy J. Brocksom、Alcindo A. Dos Santos
DOI:10.1016/j.tet.2014.02.017
日期:2014.5
A mild solvent-free protocol for the promotion of the Diels–Alder reactions of simple dienes and p-benzoquinones, catalyzed by a mixture of iron(III) chloride on Aerosil® silica is reported.