Synthesis, characterization, X‐ray crystal structure and in vitro antitumour activity of bis(1,2‐dicarba‐closo‐dodecaborane‐9‐carboxylato)di‐n‐butyltin

Abstract

The 1 : 2 condensation of dibutyltin(IV) oxide with 1,2-carborane-9-carboxylic acid resulted in bis(1,2-dicarba-closo-dodecaborane-9-carboxylato)di-n-butyltin (1), the first carborane-based organotin compound where the carborane cage is linked to the carboxylic moiety via a boron atom. The structure of 1, characterized by 1 H, 11 B, 13 C, 119 Sn NMR spectroscopy and X-ray diffraction, was shown to correspond to bis(1,2-dicarba-closo-dodecaborane-9-carboxylato)di-n-butyltin. Compound 1 was screened in vitro against seven tumour cell lines of human origin and was found to be significantly more active than 5-fluorouracil, cis-platin and carboplatin but less active than methotrexate and doxorubicin.

Metal-containing carboranes with antitumor activity

“…28 Then symmetrization with cadmium amalgam in acetone or the reaction with lithium naphthalene in THF afforded bis (o carboranyl)mercury and bis (m carboranyl)mercury, respectively. 29 The reactions of these compounds with SnCl 2 produce the corresponding bis(o carboranyl)tin dichloride (1,2 C 2 B 10 H 11 9 ) 2 SnCl 2 (38) and bis(m carboranyl)tin dichloride (1,7 C 2 B 10 H 11 9 ) 2 SnCl 2 (39). 30 Bis(car boranyl)tin dichlorides react with alkali to form the cor responding oxides (1,2 C 2 B 10 H 11 9 ) 2 SnO (40) and (1,7 C 2 B 10 H 11 9 ) 2 SnO (41) 31 (Scheme 11).…”

“…39 Tin derivatives containing three organic substituents and having the general formula R´C(O)OSnR 3 are rather well known as bactericides and fungicides. In this con nection, these compounds were tested for antitumor ac tivity.…”

“…In vitro antitumor activity IC 50 (ng mL -1 ) of compounds 42-44 against the cell lines MCF 7 and EVSA T (two types of breast cancers), IGROV (ovarian cancer), M19 MEL (skin cancer, melanoma), and A498 (renal cancer) compared to the clinically used drugs, carborane o C 2 B 10 H 12 , and (m C 2 B 10 H 11 9) 2 SnCl 2(39) …”

Synthesis, characterization, X‐ray crystal structure and in vitro antitumour activity of sodium bis(2‐(3′,6′,9′‐trioxadecyl)‐1,2‐dicarba‐closo‐dodecaborane‐1‐carboxylato)triphenylstannate

“…Some of them contain a carborane cage linked to the tin atom via a B-Sn σ -bond. 3 Organotin carboranecarboxylates in which the carborane cage is linked to the carboxylic moiety via a carbon 4,5 or boron 6 atom have been studied. All carborane-based organotin compounds previously tested have revealed in vitro antitumour activities that are less than those of the clinically used methotrexate and doxorubicin, but greater than those of 5-fluorouracil, cis-platin and carboplatin.…”

A boron cluster with a pair of carboxylic acid groups on adjacent borons: Synthesis and structure of 7,12-(COOH)2-CB11H10−

“…The chemistry of the CB 11 − cluster has been the subject of extensive study and a variety of derivatives of 1 have been prepared [5]. A number of C-substituted derivatives of 1 have been synthesized by a general route involving deprotonation of the carbon vertex and subsequent reaction with an electrophile.…”