TY - JOUR
T1 - Interception and Synthetic Application of Diradical and Diene Forms of Dual-Nature Azabicyclic o-Quinodimethanes Generated by 6π-Azaelectrocyclization
AU - Shankar, Majji
AU - Lee, Daniel J.
AU - Inaththappulige, Supuni I.N.Hewa
AU - Acharya, Ayush
AU - Yennawar, Hemant P.
AU - Giri, Ramesh
N1 - Publisher Copyright:
© 2024 The Authors. Angewandte Chemie International Edition published by Wiley-VCH GmbH.
PY - 2024/10/7
Y1 - 2024/10/7
N2 - We demonstrate that 2-alkenylarylaldimines and ketimines undergo thermal 6π-azaelectrocyclization to generate a wide range of azabicyclic o-quinodimethanes (o-QDMs). These o-QDMs exist as a hybrid of a diene and a benzylic diradical. The diradical nature was confirmed by their ability to undergo dimerization and react with H-atom donor, 2,2,6,6-tetramethylpiperidin-1-yl)oxyl (TEMPO) and O2. In addition, the interception of the diradicaloid o-QDMs by H-atom transfer was used to synthesize five tetrahydroisoquinoline alkaloids and related bioactive molecules. The diene form can undergo [4+2] cycloaddition reactions with different dienophiles to generate bridged azabicycles in high endo:exo selectivity. The azabicyclic o-QDMs can be generated for [4+2] cycloaddition from a wide range of electronically and sterically varied 2-alkenylarylimines, including mono, di, tri and tetrasubstituted alkenes, and imines derived from arylamine, alkylamine (1°, 2°, 3°), benzylamine, benzylsulfonamide and Boc-amine.
AB - We demonstrate that 2-alkenylarylaldimines and ketimines undergo thermal 6π-azaelectrocyclization to generate a wide range of azabicyclic o-quinodimethanes (o-QDMs). These o-QDMs exist as a hybrid of a diene and a benzylic diradical. The diradical nature was confirmed by their ability to undergo dimerization and react with H-atom donor, 2,2,6,6-tetramethylpiperidin-1-yl)oxyl (TEMPO) and O2. In addition, the interception of the diradicaloid o-QDMs by H-atom transfer was used to synthesize five tetrahydroisoquinoline alkaloids and related bioactive molecules. The diene form can undergo [4+2] cycloaddition reactions with different dienophiles to generate bridged azabicycles in high endo:exo selectivity. The azabicyclic o-QDMs can be generated for [4+2] cycloaddition from a wide range of electronically and sterically varied 2-alkenylarylimines, including mono, di, tri and tetrasubstituted alkenes, and imines derived from arylamine, alkylamine (1°, 2°, 3°), benzylamine, benzylsulfonamide and Boc-amine.
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U2 - 10.1002/anie.202409613
DO - 10.1002/anie.202409613
M3 - Article
C2 - 39024419
AN - SCOPUS:85205526495
SN - 1433-7851
VL - 63
JO - Angewandte Chemie - International Edition
JF - Angewandte Chemie - International Edition
IS - 41
M1 - e202409613
ER -