TY - JOUR
T1 - The anionic Fries rearrangement
T2 - a convenient route to ortho-functionalized aromatics
AU - Korb, Marcus
AU - Lang, Heinrich
PY - 2019/5/21
Y1 - 2019/5/21
N2 - The ortho-directed lithiation of aromatic carbamates and carbonates causes a migration of the substituent from the pendant O group to the adjacent C atom of the aromatic scaffold. This reaction, resulting in the formation of ortho-hydroxycarbonyl compounds, is widely known as the anionic Fries rearrangement, and is described in terms of the migrating group as a 1,3-OC shift. The intramolecular mechanism allows for a control of regioselectivity by a metalation procedure. Commonly known for the migration of carbonyl groups, the scope has been extended in recent years to Si-, S- and P-based versions, known as the respective anionic sila-, thia- and phospho-Fries rearrangements. Examples of higher homologues, which are sparsely investigated, will also be discussed. Starting with aromatic substrates in the 1980s organometallic backbones, e.g. ferrocenes, have also been introduced, which opened the pathway for stereoselective processes of the Fries rearrangement. Furthermore, related conversions, such as 1,2-, 1,4- (homo-Fries), 1,5- (remote-Fries) and 1,6- as well as, e.g. NC, and SC migrations were reported and are included herein. The mechanisms for the Fries rearrangement and competing reactions, e.g. aryne formation, are discussed, based on, e.g., labeling experiments and DFT calculations. Redox-active ferrocenyl derivatives allowed for electrochemical investigations, revealing an influence of the electronic properties of the sandwich unit on the lithiation, rearrangement and post-functionalization behavior of the participating compounds.
AB - The ortho-directed lithiation of aromatic carbamates and carbonates causes a migration of the substituent from the pendant O group to the adjacent C atom of the aromatic scaffold. This reaction, resulting in the formation of ortho-hydroxycarbonyl compounds, is widely known as the anionic Fries rearrangement, and is described in terms of the migrating group as a 1,3-OC shift. The intramolecular mechanism allows for a control of regioselectivity by a metalation procedure. Commonly known for the migration of carbonyl groups, the scope has been extended in recent years to Si-, S- and P-based versions, known as the respective anionic sila-, thia- and phospho-Fries rearrangements. Examples of higher homologues, which are sparsely investigated, will also be discussed. Starting with aromatic substrates in the 1980s organometallic backbones, e.g. ferrocenes, have also been introduced, which opened the pathway for stereoselective processes of the Fries rearrangement. Furthermore, related conversions, such as 1,2-, 1,4- (homo-Fries), 1,5- (remote-Fries) and 1,6- as well as, e.g. NC, and SC migrations were reported and are included herein. The mechanisms for the Fries rearrangement and competing reactions, e.g. aryne formation, are discussed, based on, e.g., labeling experiments and DFT calculations. Redox-active ferrocenyl derivatives allowed for electrochemical investigations, revealing an influence of the electronic properties of the sandwich unit on the lithiation, rearrangement and post-functionalization behavior of the participating compounds.
KW - DIRECTED ORTHO-METALATION
KW - C-13 NMR-SPECTRA
KW - STEREOSELECTIVE P-O
KW - REGIOSELECTIVE SYNTHESIS
KW - BOND FORMATION
KW - 1,3-CARBANIONIC REARRANGEMENTS
KW - TRIARYLSULFONIUM SALTS
KW - FERROCENYL PHOSPHATES
KW - REGIOSPECIFIC ROUTE
KW - EFFICIENT SYNTHESIS
U2 - 10.1039/c8cs00830b
DO - 10.1039/c8cs00830b
M3 - Review article
C2 - 31066387
SN - 0306-0012
VL - 48
SP - 2829
EP - 2882
JO - Chemical Society Reviews
JF - Chemical Society Reviews
IS - 10
ER -