Divergent Synthesis of 1,2,3,4‐Tetrasubstituted Cyclobutenes from a Common Scaffold: Enantioselective Desymmetrization by Dual‐Catalyzed Photoredox Cross‐Coupling
作者:Dawson J. Konowalchuk、Dennis G. Hall
DOI:10.1002/anie.202313503
日期:2023.12.4
The metallaphotoredox-enabled enantioselective desymmetrization of a novel dibromocyclobutene facilitates access to a versatile cyclobutene intermediate that can be functionalized to access a wide range of chiral 1,2,3,4-tetrasubstituted cyclobutenes and cyclobutanes.
Enantioselective La<sup>III</sup>-pyBOX-Catalyzed Nitro-Michael Addition to (<i>E</i>)-2-Azachalcones
作者:Gonzalo Blay、Celia Incerti、M. Carmen Muñoz、José R. Pedro
DOI:10.1002/ejoc.201201579
日期:2013.3
[La(OTf)3] complex with a new pyBOX ligand bearing a bulky 1-naphthylmethyl substituent at the 4′-position of the oxazoline ring catalyzes the conjugate addition of nitroalkanes to a broad range of (E)-2-azachalcones, providing the expected nitro-Michael products with good yields and enantiomeric excesses up to 87 %. The optical purity of the products can be increased by a single crystallization. A plausible