The asymmetric reduction of imidazolinones with trichlorosilane.

It is shown how imidazolinones are reduced by trichlorosilane in a highly enantioselective fashion when treated with a novel Lewis base organocatalyst that is based on a 2,2'-bispyrrolidine core. Under mild reaction conditions and with low catalyst loading the hydrosilylation reaction provides a broad range of chiral imidazolidinones with various structural motifs including sterically demanding substituents, alkyls and aryls.

Geminal Diazides Derived from 1,3-Dicarbonyls: A Protocol for Synthesis.

Geminal diazides constitute a rare class of compounds where only a limited number of methods are available for their synthesis. We present the reaction of 1,3-dicarbonyl compounds (as exemplified by malonates, 3-oxoesters, and 1,3-diketones) with molecular iodine and sodium azide in aqueous DMSO providing a general access to geminal diazides. A broad range of geminal diazides with various structural motifs including sterically demanding substituents and ordinary functional groups were synthesized, and it was shown that the diazidation of 1,3-dicarbonyls can be selectively achieved even in the presence of other 1,3-dicarbonyls with substituents at 2-position.

The synthesis of α-azidoesters and geminal triazides.

Three simple methods for the synthesis of geminal triazides are described: Starting from 1) 3-oxocarboxylic acids, 2) iodomethyl ketones, or 3) terminal olefins, a range of triazidomethyl ketones can be constructed under mild oxidative reaction conditions by the use of IBX-SO3 K, a sulfonylated derivative of 2-iodoxybenzoic acid (IBX), and NaN3 as an azide source. This is the first report of representatives of this novel class of triazide compounds: Despite their high nitrogen content, the geminal triazides are easy to handle, even when preparative-scale syntheses are performed. (Caution: These procedures still require protective measures!) The triazides are now broadly available for further studies regarding their properties and reactivity.