Cyanosulfines: An Unexpected Reaction of N,N‐bis(trimethylsilyl)ynamines

Abstract

In 1988 we detected an alkynyl cation on tritium decay of a l-tritiumalkyne.['l Alkynediazonium salts might also generate alkynyl cations, although it is not certain from calculations whether they decompose to nitrogen and alkynyl cations."] We have described alkynediazonium salts, which are, however, not stable in either protic or nucleophilic media.L3] The most common syntheses for alkane-or arenediazonium compounds can therefore not be applied.Alkane-and arenediazonium salts can also be obtained from sulfinylamines 1 on reaction with NO'X-(Scheme I).[,, Sulfinylamines 1 are easily prepared from amines (also bissilylated amines) and thionyl chloride.[6] We intended to synthesize alkynylsulfinylamines 3 from bissilylated alkynylamines 2 a-d by reaction with thionyl chloride and to transform these into alkynediazonium salts. To our surprise we obtained not the alkynylsulfinylamines 3, but the cyanosulfines 4 (Scheme 2). proved to be identical with an independently synthesized sample of phenyl cyan~sulfine.[~"~ The cyanosulfines 4a-d smell unpleasant to repulsive. For 4c and 4d, cisltrans isomers were detected by gas chromatography and NMR spectroscopy, but 4 a and 4 b are sterically uniform. R -C E C -Sulfinylamines 3 and the cyanosulfines 4 are distinguishable by spectroscopy only with difficulty. To confirm the structure, 4 a was therefore treated with 2,3-dimethyl-l,3-butadiene. The product was 2-cyano-2-phenyl-4,5-dimethyl-3,6-dihydro-2 H-thiopyran-1 -oxide (5), which can only form from cyanosulfine 4a, but not from sulfinylamine 3a. Compound 5 was reduced with LiAlH, to the amine 6, which was characterized by spectroscopy (Scheme 3). Scheme 3. Diels-Alder reaction ofphenyl cyanosultine4a with 2.3-dimethyl-l-3-butadiene and reduction of the resulting dihydrothiopyran-S-oxide 5 with LiAIH,. RT = room temperature.

Separation of 2(3),9(10),16(17),23(24)-Tetrasubstituted Phthalocyanines with Newly Developed HPLC Phases

“…The characterization of the 2(3),9(10),16(17),23(24)-alkoxy-substituted phthalocyanines 3 − 13 is carried out by 1 H-NMR spectroscopy. , This is possible without difficulty in the case of the recently described 1(4),8(11),15(18),22(25)-tetrakis[((2-ethylhexyl)oxy)phthalocyaninato]nickel(II) ( 1 ) compounds . The 2(3),9(10),16(17),23(24)-substituted phthalocyanines 3 − 13 , however, exhibit very broad signals in the 1 H-NMR spectra, as known in general for many substituted phthalocyanines .…”

“…Separation of these isomers by HPLC methods was possible, because the steric interaction of the peripheral substituents R = OCH 2 CH(C 2 H 5 )C 4 H 9 in the 1(4),8(11),15(18),22(25)-position with each other and with the phthalocyanine core is comparatively strong. As a result of this, the planarity of the macrocycle is slightly disturbed . This can be shown with the D 2 h isomer of 1(4), 8(11),15(18),22(25)-tetrakis[((2-ethylhexyl)oxy)phthalocyani- nato]nickel(II).…”

“…For the first time, we were able to separate these constitutional isomers by chromatographic methods (MPLC, HPLC) in the case of 1(4),8(11),15(18),22(25)-tetrakis[((2-ethylhexyl)oxy)phthalocyaninato]nickel(II) ( 1 ). Separation was carried out on a commercially available nitrophenyl column, and the four isomers were completely characterized in terms of their symmetry by UV and 1 H-NMR spectroscopy …”

“…This can be shown with the D 2 h isomer of 1(4), 8(11),15(18),22(25)-tetrakis[((2-ethylhexyl)oxy)phthalocyani- nato]nickel(II). The Q-band in its UV spectrum should be split, but this effect is not observable because the real symmetry is lower than D 2 h while the macrocycle is nonplanar …”