1,3‐Dipole mit zentralem S‐Atom aus der Umsetzung von Aziden mit Thiocarbonyl‐Verbindungen: Eine unerwartete MeS‐Wanderung im Abfangprodukt eines ‘Thiocarbonyl‐aminids’ mit Dithiobenzoesäure‐methylester

Abstract

Reaction of PhN, with O-methyl thiobenzoate (Ila) and thioacetate ( l l c ) as well as with the dithio esters l l b , d at 80" yields the corresponding imidates and thioimidates 12 (Scheme 3). The formation of 12 is rationalized by a 1,3-dipolar cycloaddition of the azide and the C=S group followed by successive elimination of N, and S. In the three-component reaction of l l b , PhN3, and the sterically crowded thioketone la, 1,2,4-trithiolane 13a and 1,4,2-dithiazolidine 3a are formed in addition to 12b (Scheme 4 ) . The heterocycles 13a and 3a are trapping products of l a and 'thiocarbonyl-thiolate' 5a and 'thiocarbonyl-aminide' 2a (Ar=Ph), respectively (Scheme 6 ) . These 1,3-dipoles are formed as reactive intermediates. Surprisingly, in the presence of catalytic amounts of acids, the major product is the (methy1dithio)cyclobutyl thioimidate of type 14 (Scheme 5), formed by an acid-catalyzed MeS migration in dithiazolidine 17. A reaction mechanism is proposed in Scheme 7.') Teilweise von G. M . an der Jahresversammlung der Polnischen Chemischen Gesellschaft in Warschau, September 1994, vorgetragen.

The dimer, trimer and 1,2,4-trithiolane of adamantanethione

“…However, compound (IV) has also been obtained when (I) was the only sulfur compound present in the reaction mixture, such as in reactions of (I) with organic azides Mloston, Romanski, Linden et al, 1996) and with tributylammonium¯uoride (Mloston, Prakash et al, 2002). A reaction mechanism for the formation of 1,2,4-trithiolanes from thioketones and organic azides has been proposed Mloston, Romanski et al, 1995). As part of their full characterization, lowtemperature X-ray crystal structure determinations of compounds (II), (III) and (IV) were carried out.…”