Atomic oligo

Peptoids are an archetypal and relatively conservative example of a peptidomimetic oligomer (Tab. 1.1). In fact, the sequence of atoms along the peptoid backbone is identical to that of peptides. However, peptoids differ from peptides in the marmer of side chain appendage. Specifically, the side chains of peptoid oligo-... 

Phospholes can readily be prepared on a large scale and are known with a vast range of substituants [6, 16b,c]. However, the synthesis of oligo(phosphole)s analogous to (C) (Fig. 1) is a real synthetic challenge since the low aromatic character of phosphole prevents the functionalisation of the P-Ca,a carbon atoms via electrophilic substitution and inhibits their preparation using electropolymerisation. As a consequence, no poly(phosphole)s have yet been reported, although bi- and tetra-phospholes have been prepared by stepwise routes (Scheme 2). 

The reactions of mercury(II) salts with oligo-amines afford informative examples for the fact that counterions induce the formation of a distinct complex or select a distinct complex in an equilibrium to crystallize with. Thus, Hg11 acetate with dien under exactly the same reaction conditions, in the presence of C104- or PF6-, yields the dinuclear complex [Hg2(dien)3](C104)4 or the mononuclear species [Hg(dien)(H20)](PF6)2, respectively, both characterized by IR, H, and 13C NMR spectrometries, by fast-atom bombardment (FAB) MS, cyclovoltammetry, and X-ray structure analyses.209 In the first compound Pna2, Z = 4), one Hg adopts five-coordination with one tridentate and one bidentate dien ligand, which with the remaining N-donor binds to the... 

It is hoped that, exploiting the coordinating ability of oligo-a-pyridylamines with more and more nitrogen atoms, longer and longer metal string complexes will become available. 

Isonitriles react with oligo- and disilanes or silylstannanes to yield 1,1-addition products in which both Group 14 elements add to the same carbon atom of the substrate rather than across the C-N triple bond. Ito and coworkers report that palladium complexes, such as Pd(PPh3)4 and Pd(OAc)2, effectively mediate these insertion reactions, an example of which is shown in Eq. (27).78... 

From their study of the H-NMR spectra of oligo(dienyl)lithiums prepared from butadiene and isoprene, Morton et al. concluded 141,142) that in hydrocarbon solution the lithium is essentially o-bonded to the terminal carbon atom with no detectable... 

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