- Cycloaddition of Benzothiete and Electron-deficient Nitriles
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The o-quinoid 8? electron system 2, generated by thermal ring opening of benzothiete (1), enters regiospecific (8? + 2?) cycloaddition reactions with electron-deficient nitriles 3a-d, yielding the 4H-1,3-benzothiazines 4a-d.A competitive dimerization of 1
- Schmidt, Michael,Meier, Herbert,Saleh, Sadiq A.
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p. 573 - 575
(2007/10/02)
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- 4H-3,1-Benzoxathiines from Benzothiete and Carbonyl Compounds
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The o-quinoid 8-? electron system 2, generated by thermal ring opening of benzothiete (1) undergoes cycloaddition reactions with electron-deficient carbonyl compounds 3.In accordance with the frontier orbital theory, 4H-3,1-benzoxathiines (4) are obtained in a regioselective manner.
- Schmidt, Michael,Meier, Herbert,Niedermann, Hans-Peter,Mengel, Rudolf
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p. 1143 - 1148
(2007/10/02)
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- Cycloaddition of Benzothiete to 4-Substituted Styrenes
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By thermal ring opening benzothiete (1) generates an 8-? electron system 2, which forms the cycloadducts 4/5a-j with 4-substituted styrenes 3a-j.The enhancement of the reactivity by electron-donating as well as electron-withdrawing substituents and their influence on the regioselectivity are discussed by applying frontier orbital calculations. - Key Words: Cycloaddition; Substituent effects; Reactivity; Regioselectivity; FMO calculations
- Meier, Herbert,Schmidt, Michael,Eckes, Heinz-Ludwig
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p. 1545 - 1550
(2007/10/02)
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- Cycloaddition Reactions of Benzothiete with Azomethines
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A new synthetic route to 3,4-dihydro-2H-1,3-benzothiazines 5 has been developed by the regiospecific cycloaddition of Schiff bases 4 and benzothiete 1, which is primarily opened by heating to the corresponding o-quinoidal form 2.
- Jacob, Dominic,Meier, Herbert
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p. 1085 - 1086
(2007/10/02)
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- CYCLOADDITON REACTIONS OF BENZOTHIETE AND HETERO DIENOPHILES FOR THE SYNTHESIS OF HETEROCYCLIC SYSTEMS
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Benzothiete (1) undergoes cycloaddition reactions with hetero dienophiles with NN-, NO- or CO- double bonds, leading to six-membered heterocyclic ring systems of 2H-3,4-dihydro-1,2,3-benzothiadiazine (3), 4H-3,1,2-benzoxathiazine (4) and 4H-3,1-benzoxathiin.
- Jacob, Dominic,Peter-Niedermann, Hans,Meier, Herbert
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p. 5703 - 5706
(2007/10/02)
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