%0 Journal Article %A Briggs, Timothy F. %A Winemiller, Mark D. %A Xiang, Bosong %A Collum, David B. %D 2001 %T Solution Structures of the Mixed Aggregates Derived from Lithium Acetylides and a Camphor-Derived Amino Alkoxide %U https://acs.figshare.com/articles/journal_contribution/Solution_Structures_of_the_Mixed_Aggregates_Derived_from_Lithium_Acetylides_and_a_Camphor-Derived_Amino_Alkoxide/3689406 %R 10.1021/jo010305b.s001 %2 https://ndownloader.figshare.com/files/5779758 %K C 2 %K solution Structures %K PhCCLi %K THF %K Mixed Aggregates Derived %K trifluoromethyl ketone %K RCCLi %K lithium cyclopropylacetylide %K 15 N NMR spectroscopies %K lithium phenylacetylide %K 13 C %K stoichiometrie %K Lithium Acetylides %K tetramer %X Low-temperature 6Li, 13C, and 15N NMR spectroscopies reveal that mixtures of lithium cyclopropylacetylide or lithium phenylacetylide (RCCLi) and a vicinal amino alkoxide derived from camphor (R*OLi) in THF/pentane afford an asymmetric (RCCLi)3(R*OLi) mixed tetramer and a C2-symmetric (RCCLi)2(R*OLi)2 mixed tetramer depending on the stoichiometries. The corresponding (RCCLi)(R*OLi)3 mixed tetramer is not observed. R*OLi-mediated additions of PhCCLi to benzaldehyde proceed with up to an 8:1 enantiomeric ratio that depend on both the choice of R*OLi and the PhCCLi/R*OLi stoichiometries. The results are considered in light of a previously proposed mechanism for the 1,2-addition to a trifluoromethyl ketone. %I ACS Publications