Rhodium(II) acetate catalysed hydrosilylation of enamides and N-vinylureas leading to 1-(trialkylsilyl)alkylamine derivatives

Abstract

The [R ~* ( O A C ) ~]catalysed hydrosilylation of enamides and N-vinylureas with dimethylphenylsilane proceeds smoothly in a regio-and site-selective manner to give l-(trialkylsilyl)alkylamine derivatives in good to high yields.

Synthesis and Structure ofN-(Silylalkyl)amides: Rhodium-Catalyzed Hydrosilylation of Enamides

“…RhCl(PPh 3 ) 3 was prepared by a published procedure. N -(Silylalkyl)amide 2k was prepared by a reaction similar to that in eq 1 …”

?-Alkyl-?-aminosilanes: Synthesis via Alkylation and Hydrosilylation

“…We have also investigated an alternative approach to ␣-aminosilanes based on a hydrosilylation reaction reported by Murai and Kato,33 who found that N-alkenyl amides and ureas will undergo rhodium acetate-catalyzed hydrosilylation with dimethylphenylsilane to give the ␣-aminosilane product 30 with high regiospecificity (Fig. 15).…”

Main group organometallics in synthesis

“…229 double bonds may be employed to promote intramolecular cyclisations of 1,5-dienes, provided an ytterbium catalyst is Intramolecular asymmetric hydrosilylation of 201, using a combination of rhodium(1) with S-BINAP gives the siloxacycle 202 in up to 96% ee.231 Rhodium catalysed hydrosilylation of N-acyl enamines results in introduction of the silyl group a-to the nitrogen atom, as in 203. 232 Asymmetric ketone hydrosilylation may also be achieved by the use of appropriate complexes of rhodium ( I ) ~~~ and a similar asymmetric reduction process of nitrones by the use of a ruthenium-BINAP combination (ee's up to 91%).234 This hydrosilylation process can also be used to prepare silanes which are chiralat silicon; reaction of 1-naphthylphenylsilane with symmetrical ketones, catalysed by a rhodium(1) BINAP catalyst, is reported to give products 204 of up to 99% ee. Subsequent reaction of 204 with methylmagnesium bromide results in conversion to the corresponding chiral silane 205 in equally high ee.…”