title: Preparation of tri- and tetrasubstituted allenes via regioselective lateral metalation of benzylic (trimethylsilyl)alkynes using TMPZnCl·LiCl.
abstract: The zincation of various 1-(trimethylsilyl)-3-aryl-1-propynes with TMPZnCl·LiCl followed by a Pd-catalyzed coupling with aryl halides provides arylated allenes in 52-92% yield. Subsequent metalation with TMPZnCl·LiCl and cross-coupling with a second different aryl halide provides regioselectively tetrasubstituted allenes in 42-70% 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.
authors: Department Chemie, Ludwig-Maximilians-Universität , Butenandtstrasse 5-13, 81377 München, Germany.
authors: Pauline
authors: P
authors: Quinio
authors: Cyril
authors: C
authors: François
authors: Ana
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authors: Escribano Cuesta
authors: Andreas K
authors: AK
authors: Steib
authors: Florian
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authors: Achrainer
authors: Hendrik
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authors: Zipse
authors: Konstantin
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authors: Karaghiosoff
authors: Paul
authors: P
authors: Knochel