Preparation of Tri- and Tetrasubstituted Allenes via Regioselective Lateral Metalation of Benzylic (Trimethylsilyl)alkynes Using TMPZnCl路LiCl
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- 作者：Pauline Quinio ; Cyril Fran莽ois ; Ana Escribano Cuesta ; Andreas K. Steib ; Florian Achrainer ; Hendrik Zipse ; Konstantin Karaghiosoff ; Paul Knochel
- 刊名：Organic Letters
- 出版年：2015
- 出版时间：February 20, 2015
- 年：2015
- 卷：17
- 期：4
- 页码：1010-1013
- 全文大小：376K
- ISSN：1523-7052
文摘
The zincation of various 1-(trimethylsilyl)-3-aryl-1-propynes with TMPZnCl路LiCl followed by a Pd-catalyzed coupling with aryl halides provides arylated allenes in 52鈥?2% yield. Subsequent metalation with TMPZnCl路LiCl and cross-coupling with a second different aryl halide provides regioselectively tetrasubstituted allenes in 42鈥?0% yield. This sequence can be performed in a one-pot procedure. DFT calculations and NMR studies support the formation of allenylzinc and propargyllithium intermediates starting from 1-(trimethylsilyl)-3-phenyl-1-propyne.