Structural effects in pyrazolidinone-mediated organocatalytic Diels–Alder reactions
作者:Eoin Gould、Tomas Lebl、Alexandra M.Z. Slawin、Mark Reid、Andrew D. Smith
DOI:10.1016/j.tet.2010.09.021
日期:2010.11
promoted Diels–Alderreactions evaluated. Systematic variation of the C(5)- and N(2)-substituents indicates that the incorporation of an electron withdrawing substitutent at N(2) and either a Ph or CF3 substitution at C(5) results in optimal catalytic activity. The diastereoisomeric resolution of a model C(5)-Ph substituted pyrazolidinone and its ability to impart modest levels of asymmetric induction
The development of highly active acyclic chiral hydrazides for asymmetric iminium ion organocatalysis
作者:Eoin Gould、Tomas Lebl、Alexandra M. Z. Slawin、Mark Reid、Tony Davies、Andrew D. Smith
DOI:10.1039/c3ob41719k
日期:——
Double asymmetric induction has been employed as a tool to optimise pyrazolidinone-derived organocatalysts for the asymmetric iminiumion catalysed Diels–Alder reaction. Mechanistic studies revealed a superior hydrazide catalyst deriving from methanolysis of the chiral pyrazolidinone precursor. This catalyst displays unusually high endo diastereoselectivity and good enantioselectivity with a range