Lawesson-type thionating reagent

The typical Wittig-type intermediates, that is, 1,3,2-oxathiaphosphetane derivatives, were isolated from the thionation reaction of .r-bicyclo[3.3.0 octane-3,7-dioncs with Lawesson s reagent <1998EJ02647>. However, under similar conditions both ketones and the corresponding thioketones formed a mixture of trans- and as-1,3,2-dithiaphosphetanes 26a and 26b and 66a and 66b (Scheme 34), <2004TL1331>. 

Synthesis of ly3-Thiazole-5(4/ ft-thiones. The preferential thionation of /V,/V-disubstituted carboxamides can be used for a convenient synthesis of 2,4,4-trisubstituted l,3-thiazole-5(4/ -thiones of type 11. Treatment of Wacylated a,a-disubstituted a-amino acid amide 10 with 1 in toluene/pyridine at 100 °C gives 11 as the sole product. In contrast, the analogous reaction with Lawesson s reagent leads exclusively to the corresponding 1,3-thiazol-5(4/0-one 12 (eq 5). ... 

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