Embedding an Allylmetal Dimer in a Chiral Cavity: The Unprecedented Stereoselectivity of a Twofold Wittig [1,2]-Rearrangement

After alpha,alpha'-dimetalation, both 2,2'-diallyloxy-1,1'-binaphthyl and 2,2'-di-2-methylallyloxy-1,1'-binaphthyl undergo the Wittig rearrangement with perfect diastereoselectivity. When racemic 1,1'-binaphthyl-2,2'-diol ("BINOL") is used as the starting material, it gives rise to a 1:1 mixt. of antipodal stereoisomers, whereas enantiomerically pure (M)-2,2'-diallyloxy-1,1'-binaphthyl affords (M)-(S,S)-1,1-(1,1'-binaphthyl-2,2'-diyl)bis(2-propen-1-ol) as the sole product. The (M)-(S,S)/(P)-(R,R) mixt. resulting from the rearrangement of racemic 2,2'-diallyloxy-1,1'-binaphthyl can be effectively subjected to a kinetic racemate resoln. by applying the Sharpless-Katsuki asym. epoxidn. The single-sided Wittig rearrangement of 2-allyloxy-2'-propyloxy-1,1'-binaphthyl proceeds without any diastereoselectivity as this substrate can only be monometalated and hence is incapable of intramol. aggregate formation which is instrumental for the obsd. stereoselectivity. [on SciFinder (R)]


Published in:
Journal of the American Chemical Society, 128, 50, 16042-16043
Year:
2006
Keywords:
Note:
CAN 146:121418
22-3
Physical Organic Chemistry
Institute of Chemical Sciences and Engineering,Ecole Polytechnique Federale,Lausanne,Switz.
Journal
0002-7863
written in English.
918826-13-8P Role: PRP (Properties), PUR (Purification or recovery), SPN (Synthetic preparation), PREP (Preparation) (crystal structure and embedding allylmetal dimer in chiral cavity on stereoselectivity of twofold Wittig [1,2]-rearrangement); 59031-22-0P; 96065-64-4P; 918825-28-2P; 918825-32-8P Role: PRP (Properties), RCT (Reactant), SPN (Synthetic preparation), PREP (Preparation), RACT (Reactant or reagent) (crystal structure and embedding allylmetal dimer in chiral cavity on stereoselectivity of twofold Wittig [1,2]-rearrangement); 99827-46-0P; 918825-30-6P; 918825-31-7P; 918826-14-9P Role: PRP (Properties), SPN (Synthetic preparation), PREP (Preparation) (crystal structure and embedding allylmetal dimer in chiral cavity on stereoselectivity of twofold Wittig [1,2]-rearrangement); 586-75-4; 602-09-5 (BINOL); 20038-12-4; 59031-18-4; 918825-29-3 Role: RCT (Reactant), RACT (Reactant or reagent) (crystal structure and embedding allylmetal dimer in chiral cavity on stereoselectivity of twofold Wittig [1,2]-rearrangement); 918825-33-9P Role: PRP (Properties), RCT (Reactant), SPN (Synthetic preparation), PREP (Preparation), RACT (Reactant or reagent) (crystal structure; crystal structure and embedding allylmetal dimer in chiral cavity on stereoselectivity of twofold Wittig [1,2]-rearrangement)
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 Record created 2007-03-07, last modified 2018-01-27


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