title: Stereoselective S(E)2' protonation of alpha-hydroxyallylsilanes mediated by a Brook rearrangement.
abstract: Brooked up! Treatment of (R,Z)-3-(tert-butyldimethylsilyl)-1-cyano-3-hydroxyprop-1-enyl carbamate with a catalytic amount of a base afforded (S,E)-3-(tert-butyldimethylsilyloxy)-1-cyanoallyl diisopropylcarbamate, showing that S(E)2'-type reaction of allylsilicates proceeds in an anti fashion. The overall process is equivalent to trapping of an enantioenriched C-chiral carbanion at the alpha-position of nitrile group in up to 77 % ee (see scheme).
authors.affiliation: Graduate School of Medical Sciences, Hiroshima University, 1-2-3 Kasumi, Minami-Ku, Hiroshima, Japan.
authors.forename: Michiko
authors.initials: M
authors.lastname: Sasaki
authors.forename: Yuri
authors.initials: Y
authors.lastname: Shirakawa
authors.forename: Masatoshi
authors.initials: M
authors.lastname: Kawahata
authors.forename: Kentaro
authors.initials: K
authors.lastname: Yamaguchi
authors.forename: Kei
authors.initials: K
authors.lastname: Takeda
mesh_terms: D002219:Carbamates / Q000138:chemical synthesis* / Q000737:chemistry; D002384:Catalysis; D017646:Organosilicon Compounds / Q000138:chemical synthesis* / Q000737:chemistry; D012821:Silanes / Q000138:chemical synthesis* / Q000737:chemistry; D013237:Stereoisomerism
chemical_list: C540663:3-(tert-butyldimethylsilyl)-1-cyano-3-hydroxyprop-1-enyl carbamate; C540664:3-(tert-butyldimethylsilyloxy)-1-cyanoallyl diisopropylcarbamate; D002219:Carbamates; D017646:Organosilicon Compounds; D012821:Silanes