Synlett 2012; 23(10): 1526-1528
DOI: 10.1055/s-0031-1290669
letter
© Georg Thieme Verlag Stuttgart · New York

A Mannich-Type Reaction at the meso-Methyl Position of the BODIPY Fluorophore

Lijing Yang
Department of Chemistry, Brock University, 500 Glenridge Ave., St. Catharines, ON, L2S 3A1, Canada, Fax: +1(905)6829020   Email: tyan@brocku.ca
,
Hongbin Yan*
Department of Chemistry, Brock University, 500 Glenridge Ave., St. Catharines, ON, L2S 3A1, Canada, Fax: +1(905)6829020   Email: tyan@brocku.ca
› Author Affiliations
Further Information

Publication History

Received: 06 January 2012

Accepted after revision: 02 April 2012

Publication Date:
25 May 2012 (online)


Abstract

Treatment of 2,6-diethyl-4,4-difluoro-1,3,5,7,8-penta­methyl-4-bora-3a,4a-diaza-s-indacene (BODIPY) with secondary amines in dihalomethane resulted in carbon–carbon bond formation at the meso-methyl position of BODIPY via Mannich-type reactions. The resulting modified BODIPY fluorophores possess high fluorescent quantum yields.

Supporting Information

 
  • References

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  • 7 Synthesis of 2,6-Diethyl-4,4-difluoro-1,3,5,7-tetramethyl-8-(N,N-diethylaminoethyl)-4-bora-3a,4a-diaza-s-indacene (2a) Diethylamine (0.65 mL, 6.28 mmol) was added to a solution of 4,4-difluoro-2,6-diethyl-1,3,5,7,8-pentamethyl-4-bora-3a,4a-diaza-s-indacene (1, 100 mg, 0.314 mmol) in dry CH2Cl2 (4.0 mL) in a reaction vial. After the sealed reaction mixture was heated to 40 °C for 3 d, the resulting products were diluted with CH2Cl2 (10 mL) and washed successively with sat. NH4Cl solution (2 × 10 mL) and brine (10 mL). The organic layer was dried (MgSO4) and concentrated under reduced pressure. The residue was purified by column chromatography on silica gel. The appropriate fractions, which were eluted with CH2Cl2–MeOH (99:1 v/v) were combined and evaporated under reduced pressure to give the title compound as an orange solid (78 mg, 62%). Rf = 0.4 (CH2Cl2–MeOH = 95:5 v/v). HRMS (EI): m/z calcd for 12C23 1H36 11B19F2 14N3: 403.29703; found: 403.29742. 1H NMR (300.1 MHz, CDCl3): δ = 1.06 (12 H, t, J = 7.3), 2.38–2.47 (10 H, m), 2.51 (6 H, s), 2.65 (6 H, m), 3.25 (2 H, m). 13C NMR (75.5 MHz, CDCl3): δ = 11.6, 12.4, 13.5, 14.8, 17.2, 27.8, 46.6, 55.1, 131.2, 132.6, 135.9, 142.3, 152.3. 11B NMR (CDCl3): δ = 0.60 (t, J = 33.2)
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