95844-69-2Relevant academic research and scientific papers
THE EFFECT OF PHENYL SUBSTITUENTS ON ELIMINATION STEREOCHEMISTRY: A MECHANISTIC MANIFOLD IN ALKOXIDE PROMOTED DECOMPOSITION OF 1-PHENYL-1-PROPYLTRIMETHYLAMMONIUM ION
Machkova, Zuzana,Zavada, Jiri
, p. 833 - 849 (2007/10/02)
Reactions of the positionally isomeric 1-phenyl-1-propyl (I) and 1-phenyl-2-propyltrimethylammonium (II) ions with CH3OK - CH3OH, t-C4H9OK - t-C4H9OH and t-C4H9OK - C6H6 systems have been investigated with aid of the deuterated analogues erythro-2-D-I, threo-2-D-I, 1-D-I and threo-1-D-II.At least five mechanistic components (anti-β-elimination, syn-β-elimination, α',β-elimination, Sommelet-Hauser rearrangement and SN2 substitution) have been found to participate in the reaction of the quaternary compound I, in proportions varying greatly with base-solvent combination.The corresponding reactions of the isomeric compound II proceeded in a more simple manner, withount the intervention of ylide pathways in the olefin as well as in the amine formation.The stereochemistry of β-elimination determined for the two phenyl-substituted 'onium compounds has been compared with that reported previously for structurally related aliphatic analogues.The "anomalously" low propensity for syn-elimination as well as the "anomalously" high values of trans/cis-olefin rations in anti-elimination stigmatizing the presence of phenyl substituents are proposed to originate from a lack of base-approach hindrance in the reaction.
