Facile synthesis of symmetrical ethers is achieved by either trimethylsilyl triflate or trimethylsilyl iodide catalyzed reductive coupling of carbonyl compounds (aldehydes and ketones) with trialkylsilanes. The method was also extended to the trimethylsilyl iodide catalyzed preparation of unsymmetrical ethers by reductive condensation (of carbonyl compounds) with alkoxysilanes. The scope and limitations of the reactions are discussed with emphasis on diastereoselectivity.

V-(Trifluoroacetyl)indoles (3) are produced in high yield from appropriately ring-substituted JV-(trifluoroacetyl)-2-anilino acetals (2) in boiling trifluoroacetic acid containing excess trifluoroacetic anhydride. Mild saponification provides the free indoles nearly quantitatively. The scope of the reaction is discussed. The ring closure follows solvolytic substitution of a trifluoroacetoxy group for one of the ethoxy groups in 2. The method has been extended to cyclization of N-(trifluoroacety 1) --anilinoacetone in hot polyphosphoric acid followed by saponification to yield 3-methylindole.The biochemical importance of many indole derivatives2 has spurred continual efforts toward new or improved methods for synthesis of the indole nucleus.2"4 One early

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Reductive coupling of the aldehydes or ketones (I) in the presence of trimethylsilyl triflate and triethylsilane yields the symmetrical ethers (II).