Beilstein J. Org. Chem.2009,5, No. 56, doi:10.3762/bjoc.5.56
flow system for the synthesis of enantioenriched diarylmethanols from aldehydes is described. The system uses an amino alcohol-functionalized polystyrene resin as the catalyst, and the arylating agent is conveniently prepared by transmetallation of triarylboroxins with diethylzinc.
Keywords
: asymmetric synthesis; continuous flow; diarylmethanols; solid-supported catalyst; triarylboroxins; Introduction
Diarylmethanols constitute the basic scaffold in several important drugs such as antihistamines and muscle relaxants (R)-neobenodine, (R)-orphenadrine or (S)-carbinoxamine (Figure 1) [1]. Despite
the initial reaction with the boronic acid (Scheme 1).
On the other hand, triarylboroxins, easily prepared from the corresponding arylboronic acids by thermally induced dehydration under vacuum, have recently been applied with success as the starting materials for the preparation of the ArZnEt species
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Graphical Abstract
Figure 1:
Biologically active diarylmethanol derivatives.