Polycyclic Ring Formation
Using Bis-diazolactams for
Cascade Stitching
Sara A. Bonderoff
Albert Padwa
10.1021/acs.joc.6b02663.s002
https://acs.figshare.com/articles/dataset/Polycyclic_Ring_Formation_Using_Bis-diazolactams_for_Cascade_Stitching/4498481
The
chemoselective reaction of donor/acceptor (D/A) and acceptor/acceptor
(A/A) diazo moieties in the same molecule was examined using 3-diazo-1-(ethyl
2-diazomalonyl)indolin-2-one under rhodium(II) catalysis. The metallo
carbenoid derived from the D/A diazo group is preferentially formed
and undergoes selective CH, NH, and OH insertion reactions, cyclopropanation,
cyclopropenation, sulfur ylide formation/2,3-sigmatropic rearrangement,
as well as nitrogen ylide formation followed by azetidine ring expansion.
The initial reaction can be paired with a subsequent tandem cascade
sequence involving dipole formation/cycloaddition in either an intra-
or intermolecular sense to generate polycyclic <i>N</i>-heterocycles
in one pot, with the formation up to three new rings in a single operation.
Excellent diastereoselectivity was observed in the intramolecular
cycloaddition reaction producing 5 to 7-membered rings.
2016-12-15 00:00:00
chemoselective reaction
intramolecular cycloaddition reaction
NH
Cascade Stitching
Excellent diastereoselectivity
CH
tandem cascade sequence
Polycyclic Ring Formation
metallo carbenoid
diazo
OH insertion reactions
polycyclic N
7- membered rings
azetidine ring expansion
nitrogen ylide formation