Pub No:
128
Title:
Reactions of Protoporphyrin with Tetracyanoethylene
Authors:
DiNello, R.K. and David Dolphin
Journal:
J. Org. Chem.
Year:
1980
Pages:
45, 5196-5204
Abstract:
The vinyl groups of protoporphyrin react with tetracyanoethylene (TCNE) in a [2 + 2] reaction to give adducts containing one and two cyclobutane rings, e.g. I. In addition, the vinyl groups and the porphyrinic β-β cross-conjugated double bonds in rings A and B react with TCNE in a [4 + 2] cycloaddition reaction, giving chlorins when either ring A or B reacts or an isobacteriochlorin when both rings react. Reactions in which one vinyl group reacted in a [2 + 2] and the other in a [4 + 2] fashion were also observed.

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