A Rational Synthetic Approach to 2,5‐Diphenyl‐β‐silyl Phospholes

Abstract

Systematic access to β-silyl-substituted phospholes is reported. The synthesis proceeds through the addition of lithium phosphanide to a diyne and silylation of the intermediate β-lithio phosphole. By following this approach, mono and disilylation has been accomplished and the reactivity of the β-silyl phospholes towards oxidation with chalcogens and conversion into phospholides has been explored. The silyl units have

[​4+2] versus [​2+2] Homodimerization in P(V) Derivatives of 2,4-Disubstituted Phospholes

“…The 31 P NMR values for 4 are in agreement with literature data [24][25][26][27]. A comparison of the 1 H and 13 C NMR data of compounds 1d, 4d, and 5d is shown in Table 4 confirming the head-to-head dimerization of compound 4d.…”

Tailoring Phospholes for Imprint of Fluorescent 3D Structures

“…We concluded that the relatively high molecular symmetry of 1 may be responsible for its tendency to crystallize. Using a recently reported general synthetic methodology to phospholes which are mono‐ or bi‐functional in the β‐position, we prepared a modified triphenylphosphole derivative 2 with an additional trimethylsilyl unit in the β‐position of the central ring to lower the molecular symmetry (Scheme ).…”

“…Compounds 1 and 2 have been prepared according to published procedures , . For the synthesis of phospholes 3 and 4 the procedure was slightly changed.…”

Organophosphorus Compounds in Organic Electronics

“…Recently, the group of Pietschnig reported an elegant approach towards 2,5‐phenyl‐3,4‐silyl‐substituted phospholes initiated by the addition of a phosphanide to diphenylbutadiyne, followed by the reaction with a suitable silyl chloride (Figure ). Compared to the monosilylated phosphole 2 , the disilylated 3 shows a bathochromic shift of emission ( λ em =496 vs. 474 nm) and increased Stokes shifts (10 326 vs. 7312 cm −1 ); however, the fluorescence quantum yield significantly drops from 18 % in 2 to only 1 % in 3 . The group of Lang has recently started to investigate phospholes decorated with electroactive substituents .…”

“…Compared to the monosilylated phosphole 2,t he disilylated 3 shows ab athochromic shift of emission (l em = 496 vs. 474 nm) and increased Stokes shifts (10 326 vs. 7312 cm À1 ); however,t he fluorescenceq uantumy ield significantly drops from 18 %i n2 to only 1% in 3. [35] The group of Lang has recently started to investigate phospholes decorated with electroactives ubstituents. [18,36] In their studies the electronic communication across the 2,5-disubstituted phosphole has been correlated with separationo ft he redox potentials of the ferrocene substituents.…”