652993-72-1Relevant academic research and scientific papers
Diastereo- and enantiomerically pure allylboronates: Their synthesis and scope
Pietruszka, Joerg,Schoene, Niklas,Frey, Wolfgang,Grundl, Li
experimental part, p. 5178 - 5197 (2009/07/18)
Allylboronates are highly attractive reagents for allyl additions. Enantiomerically pure, stable reagents with a stereogenic centre in a-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 42 d are presented.
[3,3] Sigmatropic Rearrangement of Boron-Containing Allyl Alcohols: Synthesis of Allyl Addition Reagents
Pietruszka, Joerg,Schoene, Niklas
, p. 5638 - 5641 (2007/10/03)
Enantiomerically pure reagents for allyl additions were prepared by [3,3] sigmatropic rearrangements (see scheme) followed by a separation of the diastereoisomers. The highly stable allylboronic esters with a stereogenic center α to a boron atom were used to synthesize Z-configured homoallylic alcohols with an enantiomeric excess > 94%.
