Intramolecular Diels-Alder reactions of 1-thia-3-azabutadienes. One-pot synthesis of annulated thiazines from N-(trimethylsilyl)imines and isothiocyanates
摘要:
The intramolecular [4 + 2] cycloaddition of 1-thia-3-aza dienes is described. Substituted N-(trimethylsilyl)imines 2 derived from aromatic and heteroaromatic aldehydes 1 react with isothiocyanates to form heterodienes 3, which, although not isolated, undergo intramolecular cycloaddition at 90-degrees-C to yield heteropolycyclic compounds 5 and 7. The process was found to be regioselective and stereospecific; the stereochemistry of the cycloadducts arises from an exo transition state.
Intramolecular Diels-Alder reactions of 1-thia-3-azabutadienes. One-pot synthesis of annulated thiazines from N-(trimethylsilyl)imines and isothiocyanates
作者:Jose Barluenga、Miguel Tomas、Alfredo Ballesteros、Luis A. Lopez
DOI:10.1021/jo00019a040
日期:1991.9
The intramolecular [4 + 2] cycloaddition of 1-thia-3-aza dienes is described. Substituted N-(trimethylsilyl)imines 2 derived from aromatic and heteroaromatic aldehydes 1 react with isothiocyanates to form heterodienes 3, which, although not isolated, undergo intramolecular cycloaddition at 90-degrees-C to yield heteropolycyclic compounds 5 and 7. The process was found to be regioselective and stereospecific; the stereochemistry of the cycloadducts arises from an exo transition state.
Cycloaddition reactions of heteroazadienes. The first intramolecular Diels–Alder reaction of 1-thia-3-azabutadienes
作者:José Barluenga、Miguel Tomás、Alfredo Ballesteros、Luis A. López
DOI:10.1039/c39890001487
日期:——
Substituted 1-thia-3-azabutadienes undergo intramolecular [4 + 2] cycloadditions to unactivated carbon–carbon double bonds in high yields.