title: Preparation of dithienylphospholes by 1,1-carboboration.
abstract: In this study the scope of the 1,1-carboboration reaction was extended to the preparation of mixed heterole-based conjugated π-systems. Two arylbis(alkynyl)phosphane starting materials 2 were synthesized bearing two thiophene isomers at the alkyne units and the bulky tipp-substituent (tipp=2,4,6-triisopropylphenyl) at the phosphorous atom. The bis(thienylethynyl)phosphanes 2 were converted into the corresponding 2,5-thienyl-substituted 3-borylphospholes 4 in a double 1,1-carboboration reaction sequence employing the strongly electrophilic B(C6 F5 )3 reagent under mild reaction conditions. Subsequent Suzuki-Miyaura type cross-coupling yielded the corresponding 3-phenylphospholes 7 in a one-pot procedure from phosphanes 2 in high yields. Phospholes 7 were converted into the respective phosphole oxides 8. A photophysical characterization of derivatives 7 and 8 was carried out. The results presented here demonstrate the suitability of the 1,1-carboboration reaction for the preparation of phosphole-/thiophene-based, light-emitting systems.
authors.affiliation: Organisch-chemisches Institut, Westfälische Wilhelms-Universität Münster, Corrensstrasse 40, 48149 Münster (Germany), Fax: (+49) 251-8336503.
authors.forename: Juri
authors.initials: J
authors.lastname: Möbus
authors.forename: Anzhela
authors.initials: A
authors.lastname: Galstyan
authors.forename: Andreas
authors.initials: A
authors.lastname: Feldmann
authors.forename: Constantin G
authors.initials: CG
authors.lastname: Daniliuc
authors.forename: Roland
authors.initials: R
authors.lastname: Fröhlich
authors.forename: Cristian A
authors.initials: CA
authors.lastname: Strassert
authors.forename: Gerald
authors.initials: G
authors.lastname: Kehr
authors.forename: Gerhard
authors.initials: G
authors.lastname: Erker
keywords: 1,1-carboboration; cross-coupling; phospholes; photophysics; pi-materials; thiophenes