Diastereo- and enantiomerically pure allylboronates: their synthesis and scope.
Allylboronates are highly attractive reagents for allyl additions. Enantiomerically pure, stable reagents with a stereogenic centre in alpha-position to boron are especially versatile, albeit often difficult to synthesize. Starting from boron-containing allyl alcohols 6 and 7, which are discussed in detail herein, a set of reagents were obtained via [3,3]-sigmatropic rearrangements and consecutive transformations in the side chain. The configurations could be established first by chemical correlation, but also by X-ray crystallography (16, 18, 34, and 39). Allyl additions were performed resulting in the formation of predominantly (Z)-configured homoallylic alcohols (31, 43-45) with high enantiomeric excess. Detailed investigations on the matched-mismatched interaction between the reagents 15/16 (and ent-15/ent-16, respectively) and isopropylidene glyceraldehyde 42d are presented.
Pietruszka
Jörg
J
Institut für Bioorganische Chemie der Heinrich-Heine-Universität Düsseldorf im Forschungszentrum Jülich, Stetternicher Forst, Jülich, Germany. j.pietruszka@fz-juelich.de
Schöne
Niklas
N
Frey
Wolfgang
W
Grundl
Li
L
D000438:Alcohols / Q000737:chemistry; D000498:Allyl Compounds / Q000138:chemical synthesis* / Q000737:chemistry; D001897:Boronic Acids / Q000138:chemical synthesis* / Q000737:chemistry; D005985:Glyceraldehyde / Q000031:analogs & derivatives / Q000737:chemistry; D013237:Stereoisomerism
D000438:Alcohols; D000498:Allyl Compounds; D001897:Boronic Acids; D005985:Glyceraldehyde