5123-17-1Relevant articles and documents
From Monodisperse Thienyl- and Furylborane Oligomers to Polymers: Modulating the Optical Properties through the Hetarene Ratio
Lik, Artur,Jenthra, Sangeth,Fritze, Lars,Müller, Lars,Truong, Khai-Nghi,Helten, Holger
, p. 11961 - 11972 (2018)
The application of our newly developed B–C coupling method by catalytic Si/B exchange is demonstrated for the synthesis of a series of triarylboranes (1), monodisperse thienyl- and furylborane dimers (2) and trimers (9), extended oligomers (3) and polymers (3′), as well as mixed (oligo)thienyl-/furylboranes. The structures of 1 aaTip, 1 bbTip, and 2 bbbMes*, determined by X-ray crystallography, reveal largely coplanar hetarene rings and BR3 environments, which are most pronounced in the furylborane species. Photophysical investigations, supported by TD-DFT calculations, revealed pronounced π-electron delocalization over the hetarene backbones including the boron centers. With an extended series of derivatives of varying chain lengths available, we were able to determine the effective conjugation lengths (ECL) of poly(thienylborane)s and poly(furylborane)s, which have been reached with the highest-molecular-weight derivatives of our study. Through variation of the furan-to-thiophene ratio, the photophysical properties of these materials are effectively modulated. Significantly, higher furan contents lead to considerably increased fluorescence intensities. Compounds 1 aaTip, 1 bbTip, and 3 aTip showed the ability to bind fluoride anions. The binding process is signaled by a distinct change in their optical absorption characteristics, thus rendering these materials attractive targets for sensory applications.
Catalytic B-C Coupling by Si/B Exchange: A Versatile Route to π-Conjugated Organoborane Molecules, Oligomers, and Polymers
Lik, Artur,Fritze, Lars,Müller, Lars,Helten, Holger
, p. 5692 - 5695 (2017/05/04)
Conjugated organoboranes have emerged as attractive hybrid materials for optoelectronic applications. Herein, a highly efficient, environmentally benign catalytic B-C bond formation method is presented that uses organosilicon compounds, dibromoboranes, and the metal-free organocatalyst Me3SiNTf2. This Si/B exchange approach has been successfully applied to the synthesis of arylborane molecules 4a-c, oligomers 8a,b, and polymers 8a′,b′. Photophysical investigations, supported by TD-DFT calculations, reveal highly effective π-conjugation in thienyl- and furylborane species; the latter are also highly emissive.
Total synthesis of (-)-calyciphylline N
Shvartsbart, Artem,Smith, Amos B.
supporting information, p. 870 - 873 (2014/02/14)
The total synthesis of the architecturally complex Daphniphyllum alkaloid (-)-calyciphylline N has been achieved. Highlights of the synthesis include a Et2AlCl-promoted, highly stereoselective, susbtrate-controlled intramolecular Diels-Alder re
