In quest of reversibility of Friedel-Crafts acyl rearrangements in the pyrene series
Agranat, I; Mala'bi, T; Oded, YN; Kraus, HD; ,
| HERO ID | 6931906 |
|---|---|
| In Press | No |
| Year | 2020 |
| Title | In quest of reversibility of Friedel-Crafts acyl rearrangements in the pyrene series |
| Authors | Agranat, I; Mala'bi, T; Oded, YN; Kraus, HD; , |
| Journal | Structural Chemistry |
| Volume | 31 |
| Issue | 1 |
| Page Numbers | 47-60 |
| Abstract | Friedel-Crafts acyl rearrangements in PPA of diacetylpyrenes (80-120 degrees C), dibenzoylpyrenes (80-200 degrees C), and bis(4-flurobenzoyl)pyrenes (80-120 degrees C) and Scholl reactions in AlCl3/NaCl of dibenzoylpyrenes (140-200 degrees C) have been studied. The substrates were 1-AcPY, 2-AcPY, 1,3-Ac2PY, 1,6-Ac2PY, 1,8-Ac2PY, 2,7-Ac2PY, 1-BzPY, 1,6-Bz(2)PY, 1,8-Bz(2)PY, 1-4FBzPY, 1,6-4FBz(2)PY, 1,8-4FBz(2)PY. The mixtures of pyrene, 1-AcPY, 2-AcPY, 1,3-Ac2PY, 1,6-Ac2PY, 1,8-Ac2PY, and 2,7-Ac2PY were separated by HPLC. The following reversible intermolecular isomerizations were established: 1,6-Ac2PY 1,8-Ac2PY, 1,6-Bz(2)PY 1,8-Bz(2)PY, and 1,6-4'FBz(2)PY 1,8-4'FBz(2)PY, albeit not in high yields. The results substantiate Gore's 1955 proposition that "The Friedel-Crafts acylation reaction of reactive aromatic hydrocarbons is a reversible process." The isomerizations reported here differ from the few previously reported completely reversible intramolecular Friedel-Crafts acyl rearrangements. At >= 140 degrees C, in PPA and in AlCl3/NaCl, 1,6-Bz(2)PY and 1,8-Bz(2)PY underwent a highly regioselective double Scholl reaction to give pyranthrone (3) and deacylations to 1-BzPy (and pyrene), followed by mono-Scholl reactions to give 8H-dibenzo[def,qr]chrysen-8-one (1), and 11H-indeno[2,1-a]pyren-11-one (2). The formation of 3 and not the expected tribenzo[a,ghi,o]perylene-7,16-dione (4) from 1,8-Bz(2)PY indicates that 1,8-Bz(2)PY has first undergone isomerization to 1,6-Bz(2)PY. The present study confirms the linkage between Friedel-Crafts acyl rearrangements and the Scholl reaction. |
| Doi | 10.1007/s11224-019-01460-4 |
| Wosid | WOS:000513239600005 |
| Url | https://www.scopus.com/inward/record.uri?eid=2-s2.0-85076919444&doi=10.1007%2fs11224-019-01460-4&partnerID=40&md5=afd13fa744c11814bceed709beaa7cf9 |
| Is Certified Translation | No |
| Dupe Override | No |
| Comments | Scopus URL: https://www.scopus.com/inward/record.uri?eid=2-s2.0-85076919444&doi=10.1007%2fs11224-019-01460-4&partnerID=40&md5=afd13fa744c11814bceed709beaa7cf9 |
| Is Public | Yes |
| Language Text | English |
| Keyword | Both-direction reaction; Dibenzoylpyrenes; Pyranthrone; Regioselectivity; Reversible process; Scholl reaction |