Collective Synthesis of Highly Oxygenated (Furano)germacranolides Derived from Elephantopus mollis and Elephantopus tomentosus.

Germacranolides, secondary metabolites produced by plants, have garnered academic and industrial interest due to their diverse and complex topology as well as a wide array of pharmacological activities. Molephantin, a highly oxygenated germacranolide isolated from medicinal plants, Elephantopus mollis and Elephantopus tomentosus, has exhibited antitumor, inflammatory, and leishmanicidal activities. Its chemical structure is based on a highly strained ten-membered macrocyclic backbone with an (E,Z)-dienone moiety, which is fused with an α-methylene-γ-butyrolactone and adorned with four successive stereogenic centers.

Aluminum-Hydride-Catalyzed Hydroboration of Carbon Dioxide.

This study describes the first use of a bis(phosphoranyl)methanido aluminum hydride, [ClC(PPhNMes)AlH] (, Mes = MeCH), for the catalytic hydroboration of CO. Complex was synthesized by the reaction of a lithium carbenoid [Li(Cl)C(PPhNMes)] with 2 equiv of AlH·NEtMe in toluene at -78 °C. (10 mol %) was able to catalyze the reduction of CO with HBpin in CD at 110 °C for 2 days to afford a mixture of methoxyborane [MeOBpin] (; yield: 78%, TOF: 0.