Iron hydride radical reductive alkylation of unactivated alkenes

Iron-catalyzed hydrogen atom transfer-mediated intermolecular C−C coupling reactions between alkenes and tosylhydrazones, followed by in situ cleavage of the tosylhydrazine intermediates using Et3N, are described. The process involves a new strategic bond disconnection resulting in the reductive alkylation of nonactivated alkenes. The reaction is operationally simple, proceeds under mild conditions, and has a wide substrate scope

Hydrogen Atom Transfer (HAT)-Triggered Iron-Catalyzed Intra- and Intermolecular Coupling of Alkenes with Hydrazones: Access to Complex Amines

A methodology for the coupling of alkenes with aldehyde- or ketone-derived Cbz-hydrazones to form a new C−C bond through a radical process is described. The sequence comprises an initial in situ generation of a putative iron hydride followed by a hydrogen atom transfer to an alkene, a coupling with a hydrazone, and a final reduction of the nitrogen-centered radical. Hydrogenation of the obtained hydrazines renders amines, including valuable tert-alkyl amines. KEYWORDS: HAT, iron catalysis, α-tert-amines, C−C bond formation, radical processes, synthetic method

MIMO channel metrics

Space diversity processing when suitable either at the transmitter side or at the receiver side provides a reduction on the transmitted power for the same received signal quality. The paper discusses the importance of the channel entropy in order to design, derived directly from the channel sounder, first, a system able to decide whether it is worth that the transmitter knows the channel or not (CSIT or Channel State Information at the Transmitter). Second, a channel metric is proposed in order to classify the channel regardless of the Tx-Rx space processing to be used. Among other aspects, this channel classifier would help in designing a vector quantifier to feedback the channel state information to the transmitter when CSIT is required.Postprint (published version

Iron-Catalyzed Radical Intermolecular Addition of Unbiased Alkenes to Aldehydes

The intermolecular reductive radical coupling of aldehydes with nonactivated alkenes, employing metal hydride atom transfer (MHAT) catalysis with a combination of FeII and FeIII salts, is described. This constitutes the first use of aldehydes as viable acceptor groups in MHAT reactions. The insights gained in this study led to the reexamination of the previously reported intramolecular version of the reaction, and the addition of FeII salts allowed the development of a more efficient second-generation approach