Synthesis of Heptamethine Cyanines from Furfural Derivatives

Abstract

Despite the widespread theranostic utilization of cyanine dyes (Cy7), their synthetic method is still limited with pyridine or cyclohexanone derivatives as starting materials. Herein, we report the synthesis of Cy7 from furfural derivatives. First, a one-pot reaction strategy is developed to solve the unstable problem of the Stenhouse salts. Second, a stepwise condensation strategy is exploited to regioselectively synthesize asymmetrical Cy7. The methodology possesses advantages, such as easy handling, high yield, wide substrate scopes, and good functional group tolerance.

Divergent Syntheses of Near-Infrared Light Activated Molecular Jackhammers to Eradicate Cancer Cells

“…Having established the key intermediate 2, we investigated the scope of substitutions, which are detailed in Table 2. [47][48][49][50] The symmetrical analogues ranging from 4a to 4o were synthesized by one step between 2 and heterocyclic salts 3 in the presence of NaOAc at 80 °C in EtOH, all in satisfactory yields. Various functional substituents, such as methyl (4a), carboxylic acid (4i), ester (4j), dimethylaminos (4h and 4k), 1,3-dioxoisoindolin-2-yl (4l) and dimethylcarbamoyl (4g) were well tolerated, forming the corresponding products in moderate to good yields (54-84%).…”

Synthesis and Spectroscopic Characterization of Furan-2-Carbaldehyde-d

“…To improve the accessibility of furan-2-carbaldehyde-d (1), we optimized the Vilsmeier protocol to obtain deuterated furfural in a quantitative yield starting from furan (3). Therefore, we choose DMF-d7 as the source of formyl.…”

“…Furfural is an important starting material for a large number of reactions. It plays an indispensable role in many synthetic pathways, e.g., for the synthesis of pharmaceuticals, dyes, or polymeric materials [1][2][3]. Since furfural can be obtained from renewable resources, the heterocycle has attracted reasonable interest in terms of green chemistry [4][5][6].…”

“…Besides the complete deuteration of a molecule, it is of interest to mark a specific position with an isotope label in order to track its path during a chemical transformation. Scheme 1 summarizes the known literature methods for the synthesis of furan-2-aldehyde-d (1), starting either from furfural (2), furan (3), di(furan-2-yl)ethanedione (4), or 2-(furan-2yl)-2-oxoacetic acid (5). The different synthetic strategies can be summarized as follows:…”

Recent Progress of Spectroscopic Probes for Peroxynitrite and Their Potential Medical Diagnostic Applications

“…Meanwhile, cyanines have remarkable biocompatibility; thus, they are often employed in fluorescent imaging-related clinical trials in which Indocyanine Green (ICG) has been approved by the FDA [ 98 , 99 ]. Cyanines are readily accessed by traditional pyridine or cycloalkyl ketone-initiated procedures or by furfurals derivative started protocols which were recently developed by Mo et al [ 100 ].…”