Synthesis and Characterization of 3-Chloropropyl-substituted o- Carboranes: Crystal Structures of 1,2-(1,3-Propanediyl)-o-carborane, 1-(3-Chloropropyl)-o-carborane and 1,2-Bis(3-chloropropyl)-ocarborane

Abstract

Synthesis and Characterization of 3-Chloropropyl-substituted o o o- Dedicated to Professor Walter SiebertThe reactions of the lithio-o-carborane Li 2 C 2 B 10 H 10 with ClCH 2 CH 2 CH 2 Br were studied under various conditions. While the main product is the known exo-polyhedrally cyclized 1,2-(1,3-propanediyl)-o-carborane (2), the expected 3-chloropropyl-substituted carborane products 1-(ClCH 2 CH 2 CH 2 )C 2 B 10 H 11 (3) and 1,2-(ClCH 2 CH 2 CH 2 ) 2 C 2 B 10 H 10 (4) can be obtained in a total yield of 22 %. In the presence of CuCl, the same reaction proceeded rather slowly and gave compound 3 and bis(o-carborane) (5) in small yields, with the recovery of the starting o-C 2 B 10 H 12 . Compounds 2 -4 were characterized by means of IR and NMR spectroscopy and mass spectrometry, as well as by single-crystal X-ray diffraction.