137151-64-5Relevant articles and documents
Enantioselective activation of ethers by chiral organoaluminum reagents: Application to asymmetric Claisen rearrangement
Maruoka,Banno,Yamamoto
, p. 647 - 662 (2007/10/02)
The asymmetric Claisen rearrangement of allyl vinyl ethers has been effected with a chiral organoaluminum reagent, (R)-1 or (S)-1 as an example of the enantioselectie activation of ether substrates. This method provides a facile asymmetric synthesis of various acylsilanes and acylgermanes with high optical purity. Among various trialkylsilyl substituents of chiral organoaluminum reagent 1, use of the more bulky t-butyldiphenylsilyl group exhibits the highest enantioselectivity. The conformational analysis of two possible chairlike transition-state structures of an allyl vinyl ether substrate reveals that a chiral organoaluminum reagent 1 can discriminate between these two conformations only by a difference in the orientation of α-methylene groups of ethers.