The regioselective alkylation of indoles with alcohols as alkylating reagents was developed by using Pd/C or RuCl2(PPh3)3/DPEphos {DPEphos = bis[(2‐diphenylphosphanyl)phenyl] ether}as catalysts. The reaction of indole with benzyl alcohol in the presence of Pd/C and K2CO3 at 80 °C for 24 h without any solvent under in air yielded 90 % of 3‐benzylindole. The corresponding 3‐benzylindole was obtained in 99 % yield when the reaction was catalyzed by RuCl2(PPh3)3/DPEphos in the presence of K3PO4 at 165 °C for 24 h under argon. Several types of alcohols were treated with indoles under these conditions to give the corresponding 3‐alkylated indoles in high yields (up to 99 %). This reaction may involve the catalyst‐mediated transformation of alcohols to aldehydes, nucleophilic addition of indole to the resulting aldehydes accompanied by dehydration, and then hydrogenation.

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A Convenient Synthesis of 1,3-Dithiane Derivatives by Reaction of 4-Methyl-1,3-dithiane-2-thione with Grignard Reagents and Butyllithium.-4-Methyl-1,3-dithiane-2-thione (I) reacts with an excess of the Grignard agents (II) or butyllithium (IV) in tetrahydrofuran at room temperature to produce selectively the 2-alkyl-4-methyl-1,3-dithianes ( III), whereas treatment of (I) with one equivalent of butyllithium leads to the formation of the dithianylidenedithiane (V). The 2-alkyl-2-butylthio-1,3-dithianes (VII) are prepared by butylation with butyllithium (IV) and subsequent alkylation with the bromides (VI) at low temperature. When the alkylation is performed at higher temperatures, the 2,2-dialkyl derivative (VIII) is produced. ( Mechanism). -(SUGAWARA, A.; SUGAWARA, R.; ITO, H.; TANAKA, H.; SEGAWA, T.; SATO, R.; Chem. Lett. (1991) 8, 1315-1318; Dep. Ind.

Cyclopentanon (I) läßt sich durch die Benzthiazolylsulfenamide (II) zu den Ketosulfiden (III) sulfenylieren, die nach Alkylierung mit den Alkylbromiden (IV) zu den Alkylketosulfiden (V) säurekatalysiert in die α‐Alkylcyclopentenone (VI) und Mercaptobenzthiazol (VII) gespalten werden.