Jonathan D. Selby

A remarkable inversion of structure–activity dependence on imido N-substituents with varying co-ligand topology and the synthesis of a new borate-free zwitterionic polymerisation catalyst

Ethylene polymerisation productivities of tris(pyrazolyl)methane-supported catalysts [Ti(NR){HC(Me2pz)3}Cl2] show a dramatically different dependence on the imido R-group compared to those of their TACN analogues, attributed to differences in fac-N3 donor topology; when treated with AliBu3, the zwitterionic tris(pyrazolyl)methide compound [Ti(N-2-C6H4tBu){C(Me2pz)3}Cl(THF)] also acts as a highly active, single site catalyst (TACN = 1,4,7-trimethyltriazacyclononane).

Cycloaddition reactions of transition metal hydrazides with alkynes and heteroalkynes: coupling of TiNNPh2 with PhCCMe, PhCCH, MeCN and tBuCP

The first structurally authenticated [2+2] cycloaddition products of any transition metal hydrazide complexes are reported; cycloaddition products of transition metal hydrazides with alkynes and heteroalkynes have been obtained for the first time; these are the first structurally authenticated cycloaddition products for any transition metal M=NNR(2) functional group.

New ligand platforms for developing the chemistry of the Ti=N-NR2 functional group and the insertion of alkynes into the N-N bond of a Ti=N-NPh2 ligand.

Two broadly applicable strategies for extending the available ligand platforms of the virtually unexplored terminal Ti=N-NR2 functional group are described, along with the highly selective room temperature insertion of alkynes into the N-N bond of Ti{MeN(CH2CH2NSiMe3)2}(NNPh2)(py) and the catalytic cis-diamination of PhC[triple bond]CMe by diphenylhydrazine.