Synthesis, Properties, and Functionalization of Nonsymmetric 8‐MethylthioBODIPYs

Abstract

Five new nonsymmetric BODIPY dyes based on the Biellmann methodology [NSBBs (nonsymmetrical Biellmann BODIPYs)] were prepared by condensation of pairs of different pyrroles with thiophosgene. Treatment of the resulting thioketones with MeI and BF3·Et2O/TEA yielded a wide range of products in a simple manner, with selective alkylation of each pyrrole of the indacene core and with controlled functionalization at the meso position. A comprehensive combined photophysical and computational study has been conducted to determine the impact of the alkylation pattern, as well as the role of the conformational freedom and electron coupling of 8‐phenyl and 8‐methylthio groups on the spectroscopic signatures of BODIPYs. The results and conclusions reached are compared with those for previously reported related analogues. We intend to provide key structural guidelines with regard to the factors that trigger the fluorescence responses and spectral shifts of multifunctional fluorophores of this family.

Synthesis of BODIPY dyes through postfunctionalization of the boron dipyrromethene core

“…OEt2 in the presence of triethylamine (Scheme 109). 295 The stoichiometry of the differently substituted pyrroles was varied so that the formation of cross-products would be favored. In order to favor the cross-product, the more electron-rich pyrrole had to be in excess.…”

“…Scheme 109: Synthesis of unsymmetrical dipyrryl thioketones 33e-i and meso-methylthioBODIPYs 34e-i. 295 Symmetrical 3,5-dimethyl-8-methylthioBODIPY 34b was halogenated at the 2,6-positions, affording 2,6-dihaloBODIPYs 34j,k (Scheme 110). 296 Multifunctional compounds 34j,k with four reactive handles attached directly to the BODIPY core [8-methylthio, 3,5-dimethyl, 4,4-difluoro and 2,6-dibromo (in 34j) or 2,6-diiodo (in 34k)] display orthogonal reactivity, allowing several reaction sequences with complete chemoselectivity, thereby opening a route to the preparation of intricate BODIPY derivatives in a rational manner.…”

Bringing Color to Sugars: The Chemical Assembly of Carbohydrates to BODIPY Dyes

“…The most commonly used approach to nonsymmetric BODIPYs could be viewed as a Vilsmeier‐Haack‐like reaction, [28,29] and is based on the condensation of two different pyrrole units one of which bears a carbonyl group at the C2 position (Scheme 2). The reaction is mediated by phosphorous oxytrichloride and directly yields a dipyrromethene intermediate 6 , which is difluoronborylated to 7 .…”

Development of Lysosome‐Targeted Fluorescent Probes for Cys by Regulating the Boron‐dipyrromethene (BODIPY) Molecular Structure

“…Considering that reactive oxygen species (ROS)/reactive nitrogen species (RNS) species may potentially oxidize thioethers, [57][58][59][60][61][62] the interference of ROS/RNS in the detectiono fC ys was also evaluated and the results are collectedi nF igure S11 (in the Supporting Information). It can be clearly seen that the detection of Cys with our probes (Lyso-S and Lyso-D)w as not affected by ROS/RNSs pecies.…”