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Coupling of Titanacyclopentadienes with a Cp Ligand and Elimination of One Substituent
Author(s) -
Mizukami Yuki,
Li Haijun,
Nakajima Kiyohiko,
Song Zhiyi,
Takahashi Tamotsu
Publication year - 2014
Publication title -
angewandte chemie
Language(s) - English
Resource type - Journals
eISSN - 1521-3757
pISSN - 0044-8249
DOI - 10.1002/ange.201403226
Subject(s) - indene , chemistry , substituent , alkyne , ligand (biochemistry) , ring (chemistry) , azobenzene , yield (engineering) , medicinal chemistry , stereochemistry , photochemistry , crystallography , organic chemistry , molecule , catalysis , materials science , biochemistry , receptor , metallurgy
Titanacyclopentadienes, prepared from [Cp 2 TiBu 2 ] and either two equivalents of an alkyne or a diyne, were treated with PMe 3 (3 equiv) at 50 °C for 3 h and then with azobenzene at room temperature for 12 h to give 4,5,6‐trisubstituted indene derivatives with the loss of one substituent in good yields. This reaction contrasts sharply with our previously reported reaction for the formation of 4,5,6,7‐tetrasubstituted indene derivatives without the loss of substituents by the treatment of titanacyclopentadienes with azobenzene without PMe 3 . 13 C NMR spectroscopy of the product derived from a 13 C‐enriched complex revealed that the five carbon atoms originating from a Cp ligand were arranged linearly in the trisubstituted indene derivatives, in contrast to the 4,5,6,7‐tetrasubsituted indene derivatives, in which the corresponding five carbon atoms are arranged in a ring.