title: Highly selective hydroaminomethylation of internal alkenes to give linear amines.
abstract: The application of phenoxaphosphino-modified Xantphos-type ligands (1-9) in the rhodium-catalyzed hydroaminomethylation of internal olefins to give linear amines is reported. Excellent chemo- and regioselectivities have been obtained through the use of 0.1 mol % [Rh(cod)2]BF(4)/0.4 mol % xantphenoxaphos (1), providing a practical and environmentally attractive synthetic route for the preparation of amines from internal alkenes. For the first time, both functionalized internal olefins and mixtures of internal and terminal olefins have been converted highly selectively into linear amines. Investigations of the effects of the calculated natural bite angles of ligands on hydroaminomethylation shows that the regioselectivity for the linear product follows a similar trend to that seen in the hydroformylation of internal alkenes with the aid of these ligands. Hydroaminomethylation and each of its individual steps were monitored by high-pressure infrared spectroscopy. The results suggest that hydroaminomethylations take place by a sequential isomerization/hydroformylation/amination/hydrogenation pathway.
authors.affiliation: Leibniz-Institut für Katalyse, Universität Rostock e.V. Albert-Einstein-Strasse 29a, 18059 Rostock, Germany.
authors.forename: Moballigh
authors.initials: M
authors.lastname: Ahmed
authors.forename: Raymond P J
authors.initials: RP
authors.lastname: Bronger
authors.forename: Ralf
authors.initials: R
authors.lastname: Jackstell
authors.forename: Paul C J
authors.initials: PC
authors.lastname: Kamer
authors.forename: Piet W N M
authors.initials: PW
authors.lastname: van Leeuwen
authors.forename: Matthias
authors.initials: M
authors.lastname: Beller
mesh_terms: D000475:Alkenes / Q000737:chemistry*; D000586:Amination; D000588:Amines / Q000138:chemical synthesis*; D002384:Catalysis; D006865:Hydrogenation; D008024:Ligands; D008745:Methylation; D008956:Models, Chemical; D009861:Onium Compounds / Q000737:chemistry; D012238:Rhodium / Q000737:chemistry
chemical_list: D000475:Alkenes; D000588:Amines; D008024:Ligands; D009861:Onium Compounds; C414204:phenoxaiodonium; D012238:Rhodium