Photoinduced Asymmetric Formal Siloxycarbene Insertion into sp C-H Bonds Enabled by Chiral Phosphoric Acid.

We disclosed herein an enantioselective formal siloxycarbene insertion reaction enabled by chiral phosphoric acid and blue LED irradiation. This is the first time the asymmetric siloxycarbene insertion into an sp C-H bond under transition-metal free conditions has been realized. The reaction features good isolated yields (up to 92%), high enantioselectivity (up to 99:1 ), mild reaction conditions, and good compatibility.

Advances in heterocycle synthesis through photochemical carbene transfer reactions.

Heterocyclic skeletons are commonly found in various bioactive molecules and pharmaceutical compounds, making them crucial in areas such as medicinal chemistry, materials science, and the realm of natural product synthesis. In recent years, the rapid advancements of visible light methodologies in organic synthesis have shown promising potential for the development of light-induced carbene transfer reactions. This is particularly significant as most organic molecules do not absorb visible light.

Fe-Catalyzed decarbonylative cascade reaction of N-aryl cinnamamides with aliphatic aldehydes to construct 3,4-dihydroquinolin-2(1H)-ones.

A practical Fe-catalyzed decarbonylative cascade reaction of N-aryl cinnamamides with aliphatic aldehydes to provide C3 alkylated 3,4-dihydroquinolin-2(1H)-ones is developed. Aliphatic aldehydes were oxidatively decarbonylated into 1°, 2° and 3° alkyl radicals conveniently, allowing for the subsequent cascade construction of C(sp3)-C(sp3) and C(sp3)-C(sp2) bonds via radical addition and HAS-type cyclization. The importance of the amide linkage and the selectivity of the 6-endo-trig over 5-exo-trig cyclization pathway were elucidated by experimental results and DFT calculations.