A divergent synthesis of oligoarylalkanethiols with Lewis-basic N-donor termini

• Published in: Organic & biomolecular chemistry 2010-08, Vol.8 (15), p.3552-3562
• Main Authors: Schüpbach, Björn, Terfort, Andreas
• Format: Article
• Language: English
• ISSN: 1477-0520; 1477-0539
• DOI: 10.1039/c003795h

Araliphatic thiols are key molecules for the formation of self-assembled monolayers with high long-range order. If these monolayers shall act as bases for the attachment of other molecules, the respective thiols need to carry suitable functional groups, such as the amino or the pyridine group. Due to their Lewis-basicity, these groups are not compatible with the thiol group under most reaction conditions. Here, an entry into this versatile class of compounds is presented, by using fundamental building blocks in which the thiol groups are protected as triisopropylsilyl sulfides making them compatible with many reagents including Grignard reagents and palladium catalysts. With this strategy at hand, six thiols with bi- and terphenyl backbones, one to three methylene groups, and amino or pyridine head groups became accessible in short reaction sequences. The gate to functional surfaces : Using a homologous series of triisopropylsilyl (TIPS) protected 4-bromophenylalkanethiols 1 as central building blocks, functional thiols for the generation of highly ordered self-assembled monolayers become accessible by short reaction sequences. The efficiency of this approach is demonstrated by the syntheses of six oligophenylalkanethiols with amino or pyridine head groups.