ISSN:
0044-2313
Keywords:
Diphosphenes
;
Trifluoromethyl Isocyanide
;
Cycloaddition Reactions
;
Diphosphirane Imines
;
2-Phosphinidene-1,3-azaphospholidine Derivative
;
Chemistry
;
Inorganic Chemistry
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Description / Table of Contents:
Cycloaddition Reactions of Trifluoromethyl Isocyanide with Diphosphenes. Synthesis and Structure of the new 2-Phosphinidene-1,3-azaphospholidine Derivative [2 + 1] Cycloaddition reactions of trifluoromethyl isocyanide 1 and methylisocyanide 2 with the diphosphene R—P=P—R 3a (a R = C[Si(CH3)3]3) yield the three membered heterocyclic diphosphirane imines 4 and 5, respectively. Whereas the trifluoromethyl substituted compound 4 is thermally very stable, the methylsubstitued derivative 5 slowly looses methyl isocyanide reforming the diphosphene 3a. In the reaction of 1 with R—P=P—R 3b [b R = 2,4,6-(t-Bu)3C6H2] no evidence for the formation of a three membered ring compound could be obtained. The five membered heterocycle 3-(2,4,6-Tri-t-butylphenyl)-2-[2,4,6-tri-t-butylphenyl)-phosphinidene]-1-trifluoromethyl-4, 5-bis(trifluoromethylimin)-1,3-azaphospholidine 6 was isolated as the only product together with unreacted 3b. The structure of 6, triclinic, P1, a = 1081.1(8), b = 1463.1(11), c = 1643.6(5)pm, α = 64.01(6), β = 81.22(4), γ = 74.04(5)°, Z = 2, R = 0.080, Rw = 0.085, has been elucidated by X-ray diffraction.
Notes:
[2 + 1]-Cycloadditions-Reaktionen von Trifluoromethylisocyanid 1 und Methylisocyanid 2 an das Diphosphen R—P = P—R 3a (a R = C[Si(CH3)3]3) ergeben dreigliedrige heterocyclische Verbindungen, die Diphosphiranimine 4 und 5. Während die trifluoromethylsubstituierte Verbindung 4 thermisch sehr stabil ist, verliert das methylsubstituierte Derivat 5 schon bei Raumtemperatur langsam unter Rückbildung des Diphosphens 3a Methylisocyanid. Bei der Reaktion von 1 mit R—P = P—R 3b [b R = 2, 4, 6-(t-Bu)3C6H2] findet man keinerlei Hinweise für die Bildung einer dreigliedrigen Ringverbindung. Man isoliert den fünfgliedrigen Heterocyclus 3-(2, 4, 6-Tri-t-butylphenyl)-2-[(2,4,6,tri-t-butylphenyl)-phosphiniden]-1-trifluormethyl-4,5-bis(trifluormethylimin)-1,3-azphospholidin 6 als einziges Produkt neben unumgesetzten 3b. Die Struktur von 6, triklin, P1, a = 1081,1(8), b = 1462,1(11), c = 1643,6(5)pm, α = 64,01(6), β = 81,22(4), γ = 74,04(5)°, Z = 2, R = 0,080, Rw = 0,085, konnte durch eine Einkristallröntgenstrukturanalyse bestimmt werden.
Additional Material:
1 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/zaac.19926170109
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