Intermolecular Amidation of Unactivated sp<sup>2</sup> and sp<sup>3</sup> C−H Bonds via Palladium-Catalyzed Cascade C−H Activation/Nitrene InsertionHung‐Yat Thu, Wing‐Yiu Yu, Chi‐Ming Che|Journal of the American Chemical Society|2006 This communication describes the Pd(OAc)2-catalyzed intermolecular amidation reactions of unactivated sp2 and sp3 C-H bonds using primary amides and potassium persulfate. The substrates containing a pendent oxime or pyridine group were amidated with excellent chemo- and regioselectivities. It is noteworthy that reactive C-X bonds were well-tolerated and a variety of primary amides can be effective nucleophiles for the Pd-catalyzed C-H amidation reactions. For the reaction of unactivated sp3 C-H bonds, beta-amidation of 1 degrees sp3 C-H bonds versus 2 degrees C-H bonds is preferred. The catalytic reaction is initiated by chelation-assisted cyclopalladation involving C-H bond activation. Preliminary mechanistic study suggested that the persulfate oxidation of primary amides should generate reactive nitrene species, which then reacted with the cyclopalladated complex.
Ruthenium Porphyrin‐Catalyzed Aerobic Oxidation of Terminal Aryl Alkenes to Aldehydes by a Tandem Epoxidation–Isomerization PathwayGaoxi Jiang, Jian Chen, Hung‐Yat Thu et al.|Angewandte Chemie International Edition|2008 Catalytic oxidation of 1-alkenes to aldehydes by an epoxidation–isomerization pathway with air or dioxygen as terminal oxidant has been realized for bulky ruthenium(VI) porphyrin catalysts. For the new, recyclable catalyst [RuVI(tmttp)O2], product yields of up to 99 % and total turnover numbers of up to 1144 were obtained. Supporting information for this article is available on the WWW under http://www.wiley-vch.de/contents/jc_2002/2008/z801500_s.pdf or from the author. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.
Highly Selective Metal Catalysts for Intermolecular Carbenoid Insertion into Primary CH Bonds and Enantioselective CC Bond FormationPrimäre C-H-Aktivierung! Der Rhodiumkomplex I eines Doppeltaschenporphyrins katalysiert die Carbenoidinsertion in die C-H-Bindungen von n-Alkanen mit primär/sekundär-Selektivitäten bis 11.4:1 (pro C-H-Bindung, siehe Bild). Die Funktionalisierung sekundärer C-H-Bindungen mit einem Rhodiumkomplex von Haltermans chiralem Porphyrin als Katalysator ergab maximal 93 % ee. Bei diesen Reaktionen wurden auch nach fünffacher Katalysatorrückgewinnung noch Umsatzzahlen von 6477 erreicht.
Ruthenium Porphyrin‐Catalyzed Aerobic Oxidation of Terminal Aryl Alkenes to Aldehydes by a Tandem Epoxidation–Isomerization PathwayGaoxi Jiang, Jian Chen, Hung‐Yat Thu et al.|Angewandte Chemie|2008 Die katalytische Oxidation von 1-Alkenen zu Aldehyden über eine Epoxidierung-Isomerisierung gelang mit Luft oder Disauerstoff als stöchiometrischem Oxidationsmittel in Gegenwart sperriger RuIV- oder RuVI-Porphyrin-Katalysatoren. Der wiederverwendbare Katalysator [RuVI(tmttp)O2] erreichte Produktausbeuten von 99 % bei Umsatzzahlen bis 1144. tmttp=1,3,5,7-Tetramethyl-2,4,6,8-tetraterphenylporphyrinato-Dianion.
Stereoselective Intramolecular Carbene C–H Insertion Catalyzed by Rhodium(III) Porphyrin ComplexesRhodium(III) porphyrin complexes [Rh(Por)Me] are catalytically active towards stereoselective intramolecular carbene C–H insertions of α-diazoacetamides to give <i>cis</i>-β-lactams or <i>trans</i>-γ-lactams in yields up to 99% with regioselectivities up to 100% and<i> cis</i>/<i>trans </i>ratios up to 83:17 for β-lactams.