Enantioselective Copper-Catalyzed Alkynylation of Quinolones Using Chiral P,N Ligands.

Herein we report a catalytic enantioselective alkynylation of quinolones. In this reaction, quinolones are silylated to form a quinolinium ion which then undergoes an enantioselective attack by a copper acetylide, templated by (S,S,Ra)-UCD-Phim. This gives alkynylated products (24 examples) in yields of up to 92% and enantioselectivities of up to 97%. This methodology has been applied to the synthesis of two natural products, (+)-cuspareine and (+)-galipinine.

Pd(0)/Blue Light Promoted Carboiodination Reaction - Evidence for Reversible C-I Bond Formation via a Radical Pathway.

A Pd(0)/blue light catalyzed carboiodination reaction is reported. A simple, air-stable catalytic system, utilizing [Pd(allyl)Cl]2 and DPEPhos, generated a variety of iodinated hetero- and carbocycles including oxindoles, dihydrobenzofurans, indolines, a chromane, and a tetrahydronaphthalene. This protocol was tolerant of sensitive functional groups including free carboxylic acids, phenols, and anilines, as well as pyridines, while delivering products in up to 94% yield. Support for a reversible C-I bond formation via a single electron mechanism was obtained using a deuterium labeled substrate and a stoichiometric neopentylpalladium species.