Synthesis of Polymers of Isocyanides

LFER Correlation of13C Chemical Shift in Para-Substituted Phenyl Isocyanide: Implications for Formation of a Unique Polymer

“…The unique polymer produced by the uncatalyzed polymerization of 3k had a 1 H NMR spectrum with three broad resonance manifolds centered at 6.6, 7.2, and 9.2 ppm in an approximate ratio of 2:2:1, respectively. This information was consistent with the conclusion that the Ni(II)-catalyzed process yielded a normal poly(iminomethylene) type structure, while the uncatalyzed process seemed to give a unique poly(iminoformate) type structure via an α-addition process, as illustrated in Scheme . Obviously, further work will be required to characterize this unique polymer type and confirm that the structure is a poly(iminoformate ester).…”

Chiral Architectures from Macromolecular Building Blocks

“…It was already proposed by Millich that these macromolecules would have a helical conformation as the result of a restricted rotation around the single bonds constituting the polymeric backbone. Until Nolte's report on the applicability of Ni(II) as a catalyst for the polymerization of isocyanides, routes toward polyisocyanides were limited . This transition-metal catalyst allowed the polymerization of the sterically demanding poly( tert- butyl isocyanide) ( 53 ), which subsequently could be resolved by chromatography into the left- and the right-handed helical forms using poly[( S )- sec -butyl isocyanide] as the stationary phase .…”

Helical poly(isocyanides)

“…5 Following suggestions by Millich6 we were able to demon strate in 1974 that poly(t-butylisocyanide) (1; R = t-C4H 9) can be resolved into left-handed and right-handed helices which do not racemize even at elevated temperatures.3 Subsequent studies have provided procedures for preparing helical poly(isocyanides) by helix-sense selective polymerization and have given Ph insight into the mechanism of the polymerization reaction. 7 The helical structure of a poly(isocyanide) is the result of restricted rotation around the single bonds connecting the main carbon atoms (atropisomerism). A similar hindered rotation is observed in poly(chloral) viz.…”