Let's get multicatalytic! A Ni0 catalyst complexed with a biaryldialkyl monophosphine ligand facilitates CC bond formation between styrenyl epoxides and aryl boronic acids (see scheme). X‐ray analysis of a catalytically active nickel/ligand complex supports a redox pathway involving C sp 3O bond activation. A variety of α‐substituted alcohols were generated with good reaction efficiency by a multicatalytic sequence.

Herein we report a nickel-catalyzed C-C bond-forming reaction between simple alkyl aziridines and organozinc reagents. This method represents the first catalytic cross-coupling reaction employing a nonallylic and nonbenzylic Csp(3)-N bond as an electrophile. Key to its success is the use of a new N-protecting group (cinsyl or Cn) bearing an electron-deficient olefin that directs oxidative addition and facilitates reductive elimination. Studies pertinent to elucidation of the mechanism of cross coupling are also presented.

A synthesis of the hasubanan alkaloids hasubanonine, runanine, and aknadinine via a unified route was attempted. Construction of key phenanthrene intermediates by a Suzuki coupling-Wittig olefination-ring-closing metathesis sequence allowed a convergent and flexible approach. Conversion of the phenanthrenes into the target structures was projected to involve six steps including phenolic oxidation, ketone allylation, anionic oxy-Cope rearrangement, and acid-promoted cyclization. The final step was thwarted by a pinacol-like rearrangement that delivered the unnatural isohasubanan alkaloid skeleton. The structures of the products were established by exhaustive NMR experiments and confirmed by GIAO (13)C NMR calculations of runanine, isorunanine, and three other isomers. These computations revealed some inconsistencies with the benzene solvent correction which suggest that caution should be used in employing this algorithm. The racemic synthesis of isohasubanonine was transformed into an enantioselective synthesis by the discovery that Nakamura's chiral bisoxazoline-ligated allylzinc reagent mediates the enantioselective allylation of ketone 19 in 93% ee. This method could be extended to three other structurally related ketones (92-96% ee), and the enantioselective syntheses of two other isohasubanan alkaloids, isorunanine and isoaknadinine, were accomplished. Racemic isohasubanonine was found to be an ineffective analgesic agent.

Auf zur Mehrfachkatalyse: Ein Ni0‐Biaryldialkylmonophosphan‐Katalysator vermittelt die Titelreaktion (siehe Schema). Die röntgenographische Charakterisierung eines katalytisch aktiven Nickel‐Ligand‐Komplexes spricht für eine Redoxreaktion unter C sp 3‐O‐Bindungsaktivierung. Eine Vielzahl α‐substituierter Alkohole wurde effizient durch eine Folge mehrerer katalytischer Prozesse erhalten.

Abstract-In this contribution, the Fisher-Bingham-5 (FB5) probability density function (pdf) is used to model the shape of the direction power spectral density function (psdf) of individual path components in the radio channel. The FB5 distribution is selected because, among all direction distributions, it maximizes the entropy under the constraints that the first and second distribution moments are specified. A SAGE (Space-Alternating Generalized Expectation-maximization) algorithm is derived based on this model for estimation of the parameters characterizing the direction psdf of each path component in a multi-path scenario. The performance of the SAGE algorithm is evaluated using measurement data. Preliminary results show that the estimated direction psdfs of individual path components exhibit different ovalnesses and tilt angles. These density functions are noticeably more concentrated than the corresponding footprints in the Bartlett spectrum.