TY - JOUR A1 - Shimada, Takahide A1 - Mori, Shigeki A1 - Ishida, Masatoshi A1 - Furuta, Hiroyuki T1 - Regioselectively α- and β-alkynylated BODIPY dyes via gold(I)-catalyzed direct C–H functionalization and their photophysical properties JF - Beilstein Journal of Organic Chemistry PY - 2020/// VL - 16 SP - 587 EP - 595 SN - 1860-5397 DO - 10.3762/bjoc.16.53 PB - Beilstein-Institut JA - Beilstein J. Org. Chem. UR - https://doi.org/10.3762/bjoc.16.53 KW - alkynylation KW - BODIPY KW - direct C–H functionalization KW - gold(I) N2 - A series of α- and β-ethynyl-substituted BODIPY derivatives (3a, 4a, 5a, 5b, 6a, 6b) were synthesized by gold(I)-catalyzed direct C–H alkynylation reactions of dipyrromethane and BODIPY, respectively, with ethynylbenziodoxolone (EBX) in a regioselective manner. Depending on the position of the ethynyl substituent in the BODIPY skeleton, the photophysical properties of the resulting α- and β-substituted BODIPYs are notably altered. The lowest S0–S1 transition absorbance and fluorescence bands are both bathochromically shifted as the number of substituents increases, while the emission quantum yields of the β-ethynylated derivatives are significantly lower than those of α-ethynylated ones. The current method should be useful for fine-tuning of the photophysical properties of BODIPY dyes as well as for constructing BODIPY-based building cores for functional π-materials. ER -