Synthesis, structure and photophysical properties of NIR aza-BODIPYs with F/ N 3 / NH 2 groups at 1,7-positions
摘要:
With 4-fluorostyrene as the starting material, symmetric/asymmetric fluorine-containing aza-difluor-oboradiaza-s-indacenes (aza-BODIPYs) 3-6 at 1/7-position were successfully prepared. NaN3 undertook nucleophilic aromatic substitution via replacement of F atoms of 4 to form the N-3/NH2-containing aza-BODIPYs 9 and 10. The solid-state structure of aza-BODIPY 4 was confirmed by single crystal X-ray analysis, the F-Cph bond distance of which was found to be shorter than those of the reported fluoride. These aza-BODIPYs absorb and emit in the NIR region. Surprisingly, although the withdrawing group was introduced at 1/7 positions of 3-6, the effect of the fluorine atoms to the photophysical properties is trifling. However, 9 and 10 with N-3/NH2 groups resulted in a remarkable bathochromic shift. Aza-BODIPY 10 could be also used as a turn-on fluorescent probe for pH value. Moreover, the main photo physical data are well supported and explained by cLR-PCM(CHCI3)-M06-2X/6-311 + G(2d,p)/SOS-CIS(D) calculations. (C) 2016 Elsevier Ltd. All rights reserved.
Rh(<scp>ii</scp>)-catalyzed cycloadditions of 1-tosyl 1,2,3-triazoles with 2H-azirines: switchable reactivity of Rh-azavinylcarbene as [2C]- or aza-[3C]-synthon
作者:Yuanhao Wang、Xiaoqiang Lei、Yefeng Tang
DOI:10.1039/c5cc00268k
日期:——
The Rh(II)-catalyzed formal [3+2] and [3+3] cycloadditions of 1-tosyl 1,2,3-triazoles with 2H-azirines have been developed, which enable the efficient synthesis of polysubstituted 3-aminopyrroles and 1,2-dihydropyrazines, respectively. The reported [3+2] cycloaddition represents the first application of 1-sulfonyl 1,2,3-triazole as a [2C]-component in relevant cycloaddition reactions.
One-Pot Three-Component Synthesis of Enamine-Functionalized 1,2,3-Triazoles via Cu-Catalytic Azide–Alkyne Click (CuAAC) and Cu-Catalyzed Vinyl Nitrene Transfer Sequence
作者:Wei Zhou、Min Zhang、Hanhui Li、Wanzhi Chen
DOI:10.1021/acs.orglett.6b02850
日期:2017.1.6
derivatives have been prepared via the Cu-catalyzed three-component reaction of terminal alkyne, azide, and 2H-azirine. The reaction proceeds through insertion of vinyl nitrene into the C–Cu bond of the triazolyl-Cu species, providing an efficient and step- and atom-economic approach to the enamine-bearing polysubstituted 1,2,3-triazoles. The resulting triazoles were easily transformed to trisubstituted
Self-Catalyzed Rapid Synthesis of <i>N</i>-Acylated/<i>N</i>-Formylated α-Aminoketones and <i>N</i>-Hydroxymethylated Formamides from 3-Aryl-2<i>H</i>-Azirines and 2-Me/Ph-3-Aryl-2<i>H</i>-Azirines
作者:Aramita De、Sougata Santra、Grigory V. Zyryanov、Adinath Majee
DOI:10.1021/acs.orglett.0c01206
日期:2020.5.15
by the reaction of 3-aryl-2H-azirines and highly substituted 2-Me/Ph-3-aryl-2H-azirines with various carboxylic acids under ambient air within 10 min at room temperature. N-Trifluoroacetylated α-aminoketones with different substituents have been reported in the presence of trifluoroacetic acid. This protocol is equally effective to synthesize N-formylated α-aminoketone and N-hydroxymethylated formamide
Ambivalent role of metal chlorides in ring opening reactions of 2H-azirines: synthesis of imidazoles, pyrroles and pyrrolinones
作者:Sergio Auricchio、Ada M. Truscello、Mirvana Lauria、Stefano V. Meille
DOI:10.1016/j.tet.2012.06.069
日期:2012.9
the presence of metal salts. Imidazoles, pyrroles and new pyrrolinones derivatives are isolated in good overall yields. The role of metal salts was investigated as they can act as Lewis acids or electron donors. Mechanisms are proposed suggesting that imidazoles arise from addition of azirine to imines via radical or ionic mechanism; pyrroles and pyrrolinones are obtained from azirines with enamino