Synthesis of chelate derivatives of o-carboranes with a ? bond between carbon and transition metals

Sulfur, tin and gold derivatives of 1-(2′-pyridyl)-ortho-carborane, 1-R-2-X-1,2-C2B10H10(R = 2′-pyridyl, X = SH, SnMe3or AuPPh3)

“…Dry Et 2 O and THF were obtained by reflux and distillation over Na wire. 4 Demineralised water was used in the aqueous stages of syntheses. Compound 3 was prepared by the literature methods.…”

“…A copper derivative 1-R-2-Cu-1,2-C 2 B 10 H 10 synthesised from the lithio derivative of 1 (R= Et) with copper(I) chloride was found to be air-sensitive and believed to contain a Cu···N interaction. 4 With 1 (R = Me) instead of 1 (R = Et), a stable compound 2,2'-(1-R-1,2-C 2 B 10 H 10 ) 2 Cu was obtained with two 3 Cu···N interactions. Copper carboranes are apparently more stable when two or more cage C-Cu bonds are present.…”

“…[3][4][5][6][7][8] For example many metal complexes 1-R-2-ML n -1,2-C 2 B 10 H 10 (with an exo-cluster C-M bond) or 1-R-2-X-3-ML n -1,2-C 2 B 9 H 9 (where ML n replaces one boron vertex) have been prepared from dialkylaminomethyl-ortho-carborane (1, R= Me or Et) [4][5][6] ( Figure 1) or from 1-(2'-picolyl)-ortho-carborane (2). 7 When a metal atom is linked to amino or picolyl nitrogen atoms in these derivatised carboranes, 5-membered C 3 NM rings are formed if a closo-C 2 B 10 cage is retained; 4-membered C 2 NM rings are found in MC 2 B 9 systems in which the ML n unit occupies a cage site.…”

“…Derivatives of ortho-carborane of formula 1-R-1,2-C 2 B 10 H 11 , bearing a nitrogen-containing substituent R on one cage carbon atom, have attracted much recent attention as potential medicinal agents for use in boron neutron capture therapy (BNCT) 1,2 and as potentially-chelating carboranyl ligand precursors. [3][4][5][6][7][8] For example many metal complexes 1-R-2-MLn-1,2-C 2 B 10 H 10 (with an exo-cluster C-M bond) or 1-R-2-X-3-MLn-1,2-C 2 B 9 H 9 (where MLn replaces one boron vertex) have been prepared from dialkylaminomethyl-ortho-carborane (1, R = Me or Et) 4-6 (Fig. 1) or from 1-(2 -picolyl)-ortho-carborane (2).…”