Moitessier, Nicolas; Maigret, Bernard; Chretien, Francoise; Chapleur, Yves published the artcile< Molecular dynamics-based models explain the unexpected diastereoselectivity of the Sharpless asymmetric dihydroxylation of allyl D-xylosides>, Application In Synthesis of 112-63-0, the main research area is xyloside ether stereoselective dihydroxylation AD mix; allyl xyloside asym dihydroxylation mol dynamics.
The catalytic asym. dihydroxylation of several allyl 2-O-benzyl-α-D-xylosides with AD-mix β and PYR(DHQD)2 shows almost no diastereofacial selectivity if the 3- and 4-OH groups are unprotected or acetylated. Acetal, benzyl ethers and benzoyl esters enhance the diastereoselectivity, in the opposite sense to that predicted by the “”AD mnemonic””, which is completely lost using AD-mix α. In an attempt to understand this behavior, computational studies of the asym. dihydroxylation (AD) of olefins using Sharpless’ and Corey’s catalysts have been carried out using mol. dynamics. A three-step algorithm was developed taking advantage of the enzyme-like behavior of catalyst-olefin systems and applied using an ESFF force field. To validate our approach, the first sampling step procedure was then refined and performed using a modified CVFF force field. This led to a U-shaped model in good agreement with that proposed by Corey for the AD of allyl 4-methoxybenzoates, which brings to the fore a role for the methoxy group. This model also accounts for the observed enantioselectivity of styrene dihydroxylation. When applied to the AD of allyl xylosides using AD-mix β, our model accounts well for the observed diastereoselectivity. Both synthetic and modeling results confirmed that aromatic groups on the olefin could be involved in π-π stacking interactions with the aromatic rings of the catalyst and should be important, if not a prerequisite, to achieve high enantio- and diastereoselectivity.
European Journal of Organic Chemistry published new progress about Dihydroxylation (stereoselective). 112-63-0 belongs to class esters-buliding-blocks, and the molecular formula is C19H34O2, Application In Synthesis of 112-63-0.
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