C-arylation and C-heteroarylation of icosahedral carboranes via their copper(I) derivatives

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)

“…9 Secondly, substitution on the cage carbon (C2) of compound 3, to form 1-(2'-pyridyl)-2-aryl-orthocarboranes, with aryl bromides or iodides in the presence of a copper catalyst is facile. 10 By contrast, attempted reaction of 1-phenyl-ortho-carborane with aryl bromides or iodides in presence of a copper catalyst did not afford 1,2-diaryl-ortho-carboranes. The formation of 1-(2'pyridyl)-2-aryl-ortho-carboranes from 3 was believed to proceed through a copper intermediate 4 (M = Cu) involving an intramolecular Cu…N interaction.…”

“…9,10 Compound 3 has two notable properties. Firstly, it contains a strong intramolecular hydrogen bond between the pyridyl nitrogen atom and the acidic hydrogen atom bonded to the cage carbon (C2), significantly stronger than the comparable intramolecular hydrogen bonds in compounds 1 and 2.…”

“…[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.…”

Substituent Effects on the Fluorescence Properties of ortho‐Carbor­anes: Unusual Emission Behaviour in C‐(2′‐Pyridyl)‐ortho‐carboranes

“…Syntheses: Compounds 1-3 were purchased commercially (KatChem) and purified by repeated sublimations, whereas 4, [68] 5, [69] 6, [68] 7, [69] 8, [70] 9, [71] 10, [71] 11, [72] 12, [73] 13, [74] 14, [74] 15, [72] 16 [75] and 17 [74] were prepared according to literature procedures. 13 Photophysical Measurements: Absorption spectra were measured from 200 to 600 nm (Δλ = 0.5 nm) with a Shimadzu absorption spectrometer.…”

Aliphatic Substitution of <i>o</i>-Carboranyl Phenols Enhances Estrogen Receptor Beta Selectivity

“…33) They were treated with n-butyl lithium to obtain the lithium salts, which were transformed into copper salts with Cu(I) Cl, and converted to the diaryl-m-carboranes 10a and b in 37% and 39% yields, respectively. 34,35) B-n-Propyl derivative 5a was synthesized by catalytic hydrogenation of the allyl group of 10a, followed by deprotection of the phenol group with BBr 3 in 45% yield over The ER binding affinities of the synthesized compounds were evaluated by means of competitive ER binding assays using [2,4,6, H]17β-estradiol and human recombinant ERα and ERβ. 36) Table 1 summarized the relative binding affinity (RBA) values, estimated based on the RBA of estradiol 2, taken as 100.…”