Silicon-pummerer rearrangements; Stereoselective sulfinylcarbanion silyation

Oxygen-to-Oxygen Silyl Migration of α-Siloxy Sulfoxides and Oxidation-Triggered Allicin Formation

Oxidation of α-siloxy thioethers leads to the formation of the corresponding sulfoxides as unstable intermediates, which undergo an intramolecular oxygen-to-oxygen silyl migration to break the C-S linkage. This process produces silyl protected sulfenic acids and subsequently thiosulfinates. It was used to develop oxidation-triggered allicin donors.

Lewis Acid-Promoted [2 + 1] Cycloaddition Reactions of a 1-Seleno-2-silylethene to 2-Phosphonoacrylates: Stereoselective Synthesis of a Novel Functionalized alpha-Aminocyclopropanephosphonic Acid

Stereoselective SnCl(4)-promoted [2 + 1] cycloaddition reactions of 1-seleno-2-silylethene 1 with 2-phosphonoacrylates 2 lead to highly functionalized cyclopropanephosphonate esters 3 in high yields. The cyclopropane products 3 are potentially versatile starting materials for biologically important compounds. Stereoselective synthesis of a novel functionalized alpha-aminophosphonic acid derivative, an analogue of (Z)-2,3-methanohomoserine 13, from the cycloadduct 3b was achieved. Stereoselectivity in the [2 + 1] cycloaddition was explained by consideration of the structure of the 2-SnCl(4) complex.