Magnesium Aldimines Prepared by Addition of Organomagnesium Halides to 2,4,6-Trichlorophenyl Isocyanide: Synthesis of 1,2-Dicarbonyl Derivatives.

The selective addition of organomagnesium reagents to 2,4,6-trichlorophenyl isocyanide leading to magnesiated aldimines is reported. These aldimines react with Weinreb amides, ketones, or carbonates to provide the corresponding carbonyl derivatives after acidic cleavage. This allows for an efficient synthesis of 1,2-dicarbonyl compounds and α-hydroxy ketones.

Highly Regioselective Remote Lithiation of Functionalized 1,3-bis-Silylated Arenes.

Substituted arenes flanked by two bulky triethylsilyl groups were regiospecifically lithiated at the 5-position with nBuLi⋅PMDTA at 25 °C. The resulting aryllithiums reacted with a broad range of electrophiles such as ketones, isocyanates, Weinreb amides, allyl bromides, and CO at 25 °C. These bis-silylated arenes were then converted in simple reaction sequences into silyl-free tetrasubstituted arenes.

Enantioselective Synthesis and Racemization of (-)-Sinoracutine.

Sinoracutine is a recently isolated alkaloid with unusual stereochemical and biological properties. It features an unprecedented tetracyclic 6/6/5/5 skeleton that bears an N-methylpyrrolidine ring fused to a cyclopentenone. Interestingly, both enantiomers of sinoracutine have been independently isolated from the same plant, yet the molecule does not appear to occur as a racemate.