129520-88-3Relevant academic research and scientific papers
Morpholine Ketene Aminal as Amide Enolate Surrogate in Iridium-Catalyzed Asymmetric Allylic Alkylation
Sempere, Yeshua,Alfke, Jan L.,R?ssler, Simon L.,Carreira, Erick M.
, p. 9537 - 9541 (2019/06/10)
Morpholine ketene aminal is employed in iridium-catalyzed asymmetric allylic alkylation reactions as a surrogate for amide enolates to prepare γ,δ-unsaturated β-substituted morpholine amides. Kinetic resolution or, alternatively, stereospecific substitution affords the corresponding products in high enantiomeric excess. The utility of the products generated by this method has been showcased by their further elaboration into amines, ketones, or acyl silanes. A putative catalytic intermediate (η3-allyl)iridium(III) with achiral P,Olefin-ligand was synthetized and characterized for the first time.
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.
