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A Stepwise [4 + 3] Cycloaddition Reaction of the 1,3-Diphenyl-2-azaallyl Anion

✍ Scribed by Mayr, Herbert ;Heigl, Ulrich W. ;Baran, Janusz

Publisher
Wiley (John Wiley & Sons)
Year
1993
Tongue
English
Weight
435 KB
Volume
126
Category
Article
ISSN
0009-2940

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✦ Synopsis

The 1,3-diphenyl-2-azaallyl anion (1) undergoes [3 + 2 1 cycloaddition reactions with the s-cis-fixed 1,3-dienes 8-11. In contrast, 1,1,2,2,3,3-hexamethyl-4,5-bis(methylene)cyclopenta- ne (7) reacts with 1 to give the [4 + 31 cycloadduct 13 and the linear l,4-addition product 14. This reaction is four orders of magnitude slower than the corresponding reaction of 1 with 1,2-bis(methy1ene)cyclopentane (8), which exclusively yields [3 + 2 1 cycloadducts. A change of mechanismconcerted

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