Tetrathia[7]helicene Phosphorus Derivatives: Experimental and Theoretical Investigations of Electronic Properties, and Preliminary Applications as Organocatalysts

Abstract

Combined experimental and theoretical study on the electronic characteristics of tetrathiahelicene (7-TH) alkyl and aryl phosphorus derivatives, including phosphanes, phosphine-borane complexes,p hosphine oxides, and phosphine-selenides, is described. The collected data give useful information on the s-donor ability of the phosphorus atoms, which mainly depends on the aryl or alkyl nature of the substituents at the phosphorus atom. Electrochemical investiga-tions provide the relationships between the electronic and structuralp roperties, and quantum chemical calculations show ac lear dominance of the 7-TH scaffold on the electronic properties of all investigated molecules. Finally,d ifferent electronic and steric properties of 7-TH phosphanes strongly influenced their catalytic behavior,f or example, as Lewis base organocatalysts in typical [3+ +2] annulation reactions.[a] Dr.[c] Dr.A .V oituriez Institut de Chimie des Substances Naturelles CNRS UPR 2301 1, av.Del aT errasse 91198 Gif-sur-Yvette (France)Supporting information and the ORCID identification number(s) for the author(s) of this article can be found under http://dx.

Synthesis, crystal structures and properties of carbazole-based [6]helicenes fused with an azine ring

“…This fact together with the exceptionally high values of specific optical rotation and strong circular dichroism have led to promising applications of helicenes. The latter have been studied with respect to conductivity [12][13][14][15], nonlinear optics [16,17], circularly polarized luminescence [18][19][20][21][22][23][24], organocatalysis [25][26][27][28][29], conformational analysis [30], chirality sensing [31], chemical sensors [32], DNA-intercalators [33,34] etc.…”

Alkyne‐Based Syntheses of Carbo‐ and Heterohelicenes

“…Helicenes exhibit large circular dichroism and large optical rotations values [1–4] . They have been studied with respect to conductivity, [5–10] nonlinear optics, [11–14] circularly polarized luminescence, [15–20] organocatalysis, [21–26] chiroptical switching activity, [27] chirality sensing, [28–30] chemical sensors, [31–33] etc.…”

“…Helicenes exhibit large circular dichroism and large optical rotations values. [1][2][3][4] They have been studied with respect to conductivity, [5][6][7][8][9][10] nonlinear optics, [11][12][13][14] circularly polarized luminescence, [15][16][17][18][19][20] organocatalysis, [21][22][23][24][25][26] chiroptical switching activity, [27] chirality sensing, [28][29][30] chemical sensors, [31][32][33] etc. The first helicenes (7H-dibenzo[c,g]carbazole and benzo[f]naphtho[2,1-c]cinnoline) were synthesized by Meisenheimer and Witte in 1903.…”

The synthesis and crystal structure of pH-sensitive fluorescent pyrene-based double aza- and diaza[4]helicenes

“…Due to this three-dimensional geometry, extended conjugated π-system and unusual optical properties, helicenes are viewed as unique candidates for optical and electronic materials. Helicenes have been studied with respect to conductivity, 1 nonlinear optics, 2 circularly polarized luminescence, 3 organocatalysis, 4 chiroptical switching activity, 5 chirality sensing, 6 chemical sensors, 7 etc . On the 100th anniversary of the chemistry of helicenes, some excellent comprehensive reviews 8 a–d and books 8 e were published.…”