A General Study of[(η5-Cp′)2Ti(η2-Me3SiC2SiMe3)]-Catalyzed Hydroamination of Terminal Alkynes: Regioselective Formation of Markovnikov and Anti-Markovnikov Products and Mechanistic Explanation (Cp′=C5H5, C5H4Et, C5Me5)
作者:Annegret Tillack、Haijun Jiao、Ivette Garcia Castro、Christian G. Hartung、Matthias Beller
DOI:10.1002/chem.200305674
日期:2004.5.17
A generalstudy of the regioselectivehydroamination of terminalalkynes in the presence of [(eta5-Cp)2Ti(eta2-Me3SiC2SiMe3)] (1), [(eta5-CpEt)2Ti(eta2-Me3SiC2SiMe3)] (CpEt=ethylcyclopentadienyl) (2), and [(eta5-Cp*)2Ti(eta2-Me3SiC2SiMe3)] (Cp*=pentamethylcyclopentadienyl) (3) is presented. While aliphatic amines give mainly the anti-Markovnikovproducts, anilines and aryl hydrazines yield the Markovnikov
A generalstudy of the regioselective hydroamination of terminalalkynes in the presence of Ti(NEt 2 ) 4 and different aryloxo and alkoxoligands is presented. Depending on the ligand the regioselectivity towards the Markovnikov and the and-Markovnikov addition product can be controlled. The experimentally observed isomer distribution is explained perfectly by detailed theoretical investigations which
A mild, convenient, and inexpensive method for converting imines into amines: Tin-catalyzed reduction with polymethylhydrosiloxane (PMHS)
作者:Rosa M. Lopez、Gregory C. Fu
DOI:10.1016/s0040-4020(97)01020-x
日期:1997.12
protocol for reducing imines to amines. Thus, treatment of any of a wide array of imines with catalytic n-butyltris(2-ethylhexanoate)tin and stoichioimetric polymethylhydrosiloxane (PMHS) in ethanol at room temperature cleanly affords the desired secondary amine product. Alkyl bromides, alkynes, epoxides, esters, nitriles, and olefins are inert toward these reduction conditions, whereas aldehydes, ketones
Controlling selectivity: from Markovnikov to anti-Markovnikov hydroamination of alkynes
作者:Annegret Tillack、Vivek Khedkar、Matthias Beller
DOI:10.1016/j.tetlet.2004.09.168
日期:2004.11
Depending on the catalyst a remarkable control of regioselectivity is achieved for the titanium-catalyzed intermolecular hydroamination of various alkynes. Proper choice of sterically hindered phenol ligands such as 1 and 4 enables a selectivity switch from the Markovnikov to the anti-Markovnikov products from M:anti-M = > 90:10 to > 10:90. (C) 2004 Elsevier Ltd. All rights reserved.
A Dramatic Effect of Aryloxo Ligands on the Titanium-Catalyzed Hydroamination of Alkynes
作者:Vivek Khedkar、Annegret Tillack、Matthias Beller
DOI:10.1021/ol035653+
日期:2003.12.1
[GRAPHICS]The aryloxotitanium complex 1 is a highly chemo- and regioselective catalyst for intermolecular hydroamination of terminal alkynes. Branched imines are obtained in good to excellent yield (up to 99%) with various primary aromatic and aliphatic amines.