13371-63-6Relevant academic research and scientific papers
Cp*2TiMe2: An improved catalyst for the intermolecular addition of n-alkyl- and benzylamines to alkynes
Heutling, Andreas,Doye, Sven
, p. 1961 - 1964 (2002)
Cp*2TiMe2 has been found to be a competent catalyst for the intermolecular addition of sterically less demanding n-alkyl- and benzylamines to internal alkynes. In the presence of 2.0-6.0 mol % of the catalyst, hydroamination reactions between n-propyl-, n-hexyl-, benzyl-, p-methoxybenzyl- or 2-phenylethylamine and diphenylacetylene, 3-hexyne or 4-octyne go to completion within 24 h or less at 114°C (oil bath temperature). After subsequent reduction of the initially formed imines with zinc-modified sodium cyanoborohydride in MeOH at 25°C, the corresponding secondary amines can be isolated in excellent yields (> 78%). Hydroamination/reduction sequences employing the unsymmetrically substituted alkyne 1-phenylpropyne give access to mixtures of regioisomeric secondary amines. The observed regioselectivity is low.
Base-catalyzed anti-Markovnikov hydroamination of vinylarenes - Scope, limitations and computational studies
Horrillo-Martinez, Patricia,Hultzsch, Kai C.,Gil, Adria,Branchadell, Vicenc
, p. 3311 - 3325 (2008/02/10)
The hydroamination of vinylarenes with primary and secondary amines was studied with catalytic amounts as low as 2 mol-% of LiN(SiMe3) 2/TMEDA. Reactions proceeded readily at 120°C in the absence of solvent to give selective anti-Markovnikov addition. Slow addition was observed at 25°C with either electron-deficient p-chlorostyrene or secondary cyclic amines such as pyrrolidine, piperidine, or morpholine. Primary amines were prone to a second hydroamination reaction to form tertiary amine byproducts. The selectivity for the mono(hydroamination) products could be improved with a two-fold excess of the amine. KN(SiMe3)2 showed higher catalytic activity but lower selectivity in comparison to that of LiN(SiMe 3)2, resulting in undesired C-H-activation by-products. The mechanism of the lithium-catalyzed hydroamination and the influence of TMEDA was studied with density functional theory. Wiley-VCH Verlag GmbH & Co. KGaA, 2007.
