posted on 2015-05-01, 00:00authored byTony S.
N. Zhao, Jian Zhao, Kálmán
J. Szabó
The
reaction of mono- and dialdehydes with bis-borodienes (incorporating
an allylboronate unit) has been studied. It was found that the initial
allylboration reaction results in an allenylboronate, which has two
stereogenic units: one of them has axial chirality and the other one
is a stereogenic carbon center. This reaction proceeds with high diastereoselectivity.
The allenylboronate formed in the allylboration reacts with an additional
aldehyde with fair to high stereoselectivity depending on the aldehyde
substrate. Aromatic dialdehydes react with bis-boro-butadienes creating
three new stereocenters with usually high diastereoselectivity.