Search

The well-defined iron(0) complex [(iPrDPBPh)Fe2-(μ-1,2-N2)] (A) reacts with HBpin to afford the complex [(η3-H2iPrDPB)Fe(η3-H2Bpin)] (B) via oxidative addition of the H–B bond. Complex A is an effective pre-catalyst for the hydroboration of a range of olefins in synthetically useful yields (typically >80%) under neat conditions. [ABSTRACT FROM AUTHOR]

Herein, we disclose the utilisation of iodonium ylides to access a range of boron dienolates. Heating of acyclic iodonium ylides in the presence of different aryl boranes leads to the formation of rare 1,3-carboboration products. This methodology could not be expanded to cyclic iodonium ylides which instead formed a Lewis acid–base adduct. Products proved to be remarkably stable under a wide range of conditions allowing for their long term storage. [ABSTRACT FROM AUTHOR]

The ability of alkali metal complexes featuring functionalized BINOL-derived ligands to catalyze ketone hydroboration reactions was explored. The reduced products were formed in excellent yields and with variable enantioselectivities dependent upon the nature of the ligand and the alkali metal cation. [ABSTRACT FROM AUTHOR]

Stabilized AlHCl2·(THF)2 hydroaluminates RC≡CH with exceptional chemo-, regio- and stereoselectivity under efficient ZrCl2(η-C5Me5)2 catalysis (2–5 mol%). The resulting vinyl alanes undergo palladium cross-coupling with a wide range of sp2 electrophiles (aryl, heteroaryl and vinyl halides/pseudohalides) in good to excellent yields. [ABSTRACT FROM AUTHOR]

Abstract: Rare alkenylalanes are prepared by Cp2TiCl2 or Cp*2ZrCl2 (Cp=η-C5H5; Cp*=η-C5Me5) catalysed addition of HAlCl2·(THF)2 to terminal alkynes (R1C CH; R1 =alkyl). Use of minimum head-volume sealed vials maximises the hydroalumination yields of volatile alkynes. Facile 1,4-addition of the resultant alkenylalanes to unsaturated malonates R2CH C(CO2R3)2 (R2 =alkyl, aryl, R3 =alkyl) is observed providing rapid and convenient access to the addition products. [Copyright &y& Elsevier]

Review: 83 refs. [ABSTRACT FROM AUTHOR]

We report a general visible-light-mediated strategy that enables the construction of complex C(sp 3 )-rich N-heterospirocycles from feedstock aliphatic ketones and aldehydes with a broad selection of alkene-containing secondary amines. Key to the success of this approach was the utilization of a highly reducing Ir-photocatalyst and orchestration of the intrinsic reactivities of 1,4-cyclohexadiene and Hantzsch ester. This methodology provides streamlined access to complex C(sp 3 )-rich N-heterospirocycles displaying structural and functional features relevant to fragment-based lead identification programs.

The study of a selective palladium(ii)-catalyzed C(sp 3 )-H acetoxylation reaction on a class of cyclic alkyl amines is reported. Computational modelling and kinetic studies were used to provide support for a mechanism involving selective C-O bond formation from a γ-aminoalkyl-Pd(iv) intermediate. The C-O bond forming step was computed to occur by a dissociative ionization mechanism followed by an S N 2 process involving external acetate attack at the C-Pd(iv) bond. This pathway was computed to be of lowest energy with no competing C-N products observed. Additionally, with a few modifications to reaction conditions, preliminary studies showed that this process could be rendered enantioselective in the presence of a non-racemic BINOL-phosphoric acid.

Stabilized AlHCl(2)·(THF)(2) hydroaluminates RC≡CH with exceptional chemo-, regio- and stereoselectivity under efficient ZrCl(2)(η-C(5)Me(5))(2) catalysis (2-5 mol%). The resulting vinyl alanes undergo palladium cross-coupling with a wide range of sp(2) electrophiles (aryl, heteroaryl and vinyl halides/pseudohalides) in good to excellent yields.