title: Practical synthesis of 1,12-difunctionalized o-carborane for the investigation of polar liquid crystals.
abstract: Two isomerically pure 1,12-difunctionalized derivatives of o-carborane, 12-iodo-1-vinyl (1b) and 12-iodo-1-phenyl (1c), are conveniently obtained on a practical scale in yields of 22% and 32%, respectively, by monoiodination of the corresponding o-carborane derivatives (4b and 4c) followed by separation of the regioisomers by crystallization (1b) and chromatography (1c). Subsequent functional group transformations gave access to other derivatives, including two liquid-crystalline compounds, in which o-carborane is a linear structural element. Regioselectivity of substitution on the carborane cage and on the benzene ring correlates with the inductive effect parameter of the substituent. The preparation of analogous derivatives of m-carborane was also investigated.
authors.affiliation: Organic Materials Research Group, Department of Chemistry, Vanderbilt University , Nashville, Tennessee 37235, United States.
authors.forename: Aleksandra
authors.initials: A
authors.lastname: Jankowiak
authors.forename: Piotr
authors.initials: P
authors.lastname: Kaszyński
mesh_terms: D001896:Boron Compounds / Q000138:chemical synthesis* / Q000737:chemistry; D050866:Liquid Crystals / Q000737:chemistry*; D015394:Molecular Structure
chemical_list: D001896:Boron Compounds