Tetraphosphorus decasulfide (P(4)S(10)) in pyridine has been used as a thionating agent for a long period of time. The moisture-sensitive reagent has now been isolated in crystalline form, and the detailed structure has been determined by X-ray crystallography. The thionating power of this storable reagent has been studied and transferred to solvents such as acetonitrile in which it has proven to be synthetically useful and exceptionally selective. Its properties have been compared with the so-called Lawesson reagent (LR). Particularly interesting are the results from thionations at relatively high temperatures (∼165 °C) in dimethyl sulfone as solvent. Under these conditions, for instance, acridone and 3-acetylindole could quickly be transformed to the corresponding thionated derivatives. Glycylglycine similarly gave piperazinedithione. At these temperatures, LR is inefficient due to rapid decomposition. The thionated products are generally cleaner and more easy to obtain because in the crystalline reagent, impurities which invariably are present in the conventional reagents, P(4)S(10) in pyridine or LR, have been removed.

Practical total syntheses of the natural products fuligocandin A (2a) and fuligocandin B (3) have been achieved through a convergent strategy depending on the Eschenmoser episulfide contraction as a key step. Conducting the reaction in DMSO proved to be an efficient and general method for the synthesis of a variety of vinylogous amides, such as azepan-2-ylidenepropan-2-one.

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A study probing the scope of acylation of indoles with dicarboxylic acids in acetic anhydride has been performed, resulting in products incorporating 3‐acylindole‐ or 1‐acylindole motifs depending on the choice of the acid reactant. Synthetically useful results were only obtained from reactions involving malonic acid or Meldrum's acid. Correlations to previous studies have also been made and discussed.

Thionations Using a P 4 S 10 -Pyridine Complex in Solvents such as Acetonitrile and Dimethyl Sulfone. -The compound (II) is an efficient thionation reagent which exhibits good solubility and thermal stability and allows formation of a wide range of thiones. -(BERGMAN*, J.; PETTERSSON, B.; HASIMBEGOVIC, V.; SVENSSON, P. H.; J. Org. Chem. 76 (2011) 6, 1546-1553, http://dx.doi.org/10.1021/jo101865y ; Unit Org. Chem., Dep. Biosci. Nutr., Karolinska Inst., S-141 57 Huddinge, Swed.; Eng.) -Jannicke 24-039

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