Ytterbium(III) Triflate-Catalyzed Amination of 1-Cyclopropylprop-2-yn-1-ols as an Expedient Route to Conjugated Enynes
摘要:
Ytterbium(III) triflate-catalyzed ring opening of substituted 1-cyclopropyl-2-propyn-1-ols with sulfonamides as an efficient synthetic route to conjugated enynes is described herein. The reaction was operationally straightforward and accomplished in moderate to good yields and recgioselective manner in all except one case under mild conditions.
Al(OTf)(3) catalyzed the alkylation of indoles using secondary/tertiary propargylic alcohols to produce 3-propargylated indoles in excellent yields with high selectivity. The reactions were performed in air with commercial grade solvents, and water was the only side product of the process. The catalyst was recovered after completion of the reaction and re-used with minimum loss of activity over three cycles. (c) 2012 Elsevier Ltd. All rights reserved.