RT Journal Article
T1 Visible Light-Mediated [4+2] Annulation of Silylimines with Olefins to 1-Aminotetralins Enabled by Diradical Hydrogen Atom Transfer of C H Bonds
A1 Liu, Quian
A1 Huang, Yao
A1 Zhou, Xiang
A1 Fernández López, Israel
A1 Xiong, Yang
AB A facile photochemical, one-pot synthesis of highly functionalized 1-aminotetralins derivatives (>70 examples) from readily accessible o-alkyl and o-formyl aryl silylimines with olefins is described. A diradical-mediated hydrogen atom transfer (DHAT) of primary, secondary, and tertiary C(sp3)−H bonds of o-alkyl arylsilylimines and C(sp2)−H bonds of o-formyl arylsilylimines enabled a [4+2] annulation with olefins in excellent diastereoselectivity. This was accomplished upon irradiation at λ = 420 nm in the presence of thioxanthen-9-one (10 mol %) as the sensitizer via energy transfer. Moreover, sulfur-substituted o-alkyl silylimines can undergo such photochemical process in the absence of an external photosensitizer. This effective protocol is compatible with a variety of functional groups and can be applied to the modification of bioactive molecules. Based on mechanistic evidences and computational studies, it is suggested that the silyl substituent enables an efficient energy transfer leading to the formation of a key C,N-diradical and subsequent [4+2]-cyclization was supported by a better molecular orbital matching between the HSOMO of the 1,4-diradical intermediate and the LUMO of the olefins. Thus, upon irradiation, the excited silylimine unlocks a carbon-to-nitrogen DHAT and subsequent [4+2] cyclization that allows the divergent functionalization of benzylic C(sp3)−H bonds and C(sp2)−H bonds.
PB Wiley
SN 1433-7851
YR 2025
FD 2025-03-10
LK https://hdl.handle.net/20.500.14352/119094
UL https://hdl.handle.net/20.500.14352/119094
LA eng
NO Liu, Q.; Huang, Y.; Zhou, X.; Fernández, I.; Xiong, Y. Visible Light‐Mediated [4+2] Annulation of Silylimines with Olefins to 1‐Aminotetralins Enabled by Diradical Hydrogen Atom Transfer of C−H Bonds. Angew Chem Int Ed 2025, 64 (11), e202421464. https://doi.org/10.1002/anie.202421464.
NO The National Natural Science Foundation of China (Grant No: 22301026), the Fundamental Research Funds for the Central Universities (Project No.2024CDJXY-002), the Natural Science Foundation of Chongqing (CSTB2024NSCQ-MSX0206), and the Hongshen Young Scholars Program from Chongqing University (02470011080002) are gratefully acknowledged for financial support. I. F. is grateful for financial support from grants PID2022-139318NB-I00 and RED2022-134331-T, funded by MICIU/AEI/10.13039/501100011033. The authors thank Dr. Thomas Rigotti (Universidad Autónoma of Madrid) for kind suggestions and for proofreading the manuscript. The authors also thank Xiang-Nan Gong (Analytical and Testing Center of Chongqing University) for X-ray crystallographic analysis.
NO The National Natural Science Foundation of China
NO Fundamental Research Funds for the Central Universities (China)
NO Natural Science Foundation of Chongqing (China)
NO Hongshen Young Scholars Program from Chongqing University (China)
NO Universidad Autónoma de Madrid
NO Ministerio de Ciencia, Innovación y Universidades (España)
DS Docta Complutense
RD 19 dic 2025