C(1)‐Phenethyl Derivatives of [closo‐1‐CB11H12]− and [closo‐1‐CB9H10]− Anions: Difunctional Building Blocks for Molecular Materials. Issue 72 (19th November 2020)

• Record Type: Journal Article
• Authors: Jakubowski, Rafał; Pietrzak, Anna; Friedli, Andrienne C.; Kaszyński, Piotr
• Is Part Of: Chemistry. Volume 26:Issue 72(2020)
• Page Start: 17481
• Page End: 17494
• Publication Date: 2020-11-19
• Subjects: boron clusters -- carborane anions -- liquid crystals -- molecular structures -- synthesis; Chemistry -- Periodicals; 540
• DOI: 10.1002/chem.202002997
• Languages: English
• ISSNs: 0947-6539

Abstract

Abstract: C(1)‐vinylation of [ closo ‐1‐CB9 H10 ] − (A ) and [ closo ‐1‐CB11 H12 ] − (B ) with 4‐benzyloxystyryl iodide followed by hydrogenation of the double bond and reductive deprotection of the phenol functionality led to C(1)‐(4‐hydroxyphenethyl) derivatives. The phenol functionality was protected as the acetate. The esters were then treated with PhI(OAc)2 and the resulting isomers were separated kinetically (for derivatives of anion A ) or by chromatography (for derivatives of anion B ) giving the difunctionalized building blocks in overall yields of 9 % and 50 %, respectively. A similar series of reactions was performed starting with anions A and B and 4‐methoxystyryl bromide and iodide. Significant differences in the reactivity of derivatives of the two carborane anions were rationalized with DFT computational results. Application of the difunctionalized carboranes as building blocks was demonstrated through preparation of two ionic liquid crystals. The extensive synthetic work is accompanied by single crystal XRD analysis of six derivatives. Abstract : Substitution of [ closo ‐1‐CB9 H10 ] − and [ closo ‐1‐CB11 H12 ] − anions with functionalized phenethyl at C(1) and iodine or PhI in the antipodal position gives new building blocks for polar and ionic liquid crystals.