Isomerizing-Hydroboration of the Monounsaturated Fatty Acid Ester Methyl Oleate

Remote Hydroamination of Disubstituted Alkenes by a Combination of Isomerization and Regioselective N-H Addition

Remote hydrofunctionalizations of alkenes incorporate functional groups distal to existing carbon-carbon double bonds. While remote carbonylations are well-known, remote hydrofunctionalizations are most common for addition of relatively nonpolar B-H, Si-H, and C-H bonds with alkenes. We report a system for the remote hydroamination of disubstituted alkenes to functionalize an alkyl chain selectively at the subterminal, unactivated, methylene position. Critical to the high regioselectivity and reaction rates are the electronic properties of the substituent on the amine and the development of the ligand DIP-Ad-SEGPHOS by evaluating the steric and electronic effects of ligand modules on reactivity and selectivity. The remote hydroamination is compatible with a broad scope of alkenes and aminopyridines and enables the regioconvergent synthesis of amines from an isomeric mixture of alkenes. The products can be derivatized by nucleophilic aromatic substitution on the amino substituent with a variety of nucleophiles.

Remote Site-Selective Asymmetric Protoboration of Unactivated Alkenes Enabled by Bimetallic Relay Catalysis

A remote C(sp³ )-H bond asymmetric borylation of unactivated alkenes was achieved by bimetallic relay catalysis. The reaction proceeded through reversible and consecutive β-H elimination/olefin insertion promoted by CoH species generated in situ, followed by copper-catalyzed asymmetric protoboration. The use of this synergistic Co/Cu catalysis protocol allowed the enantioselective protoboration of various unactivated terminal alkenes and internal alkenes, as well as an unrefined mixture of olefin isomers, at the distal less-reactive β-position to a functional group, leading to chiral organoboronates.

Ir-Catalyzed Remote Functionalization by the Combination of Deconjugative Chain-Walking and C-H Activation Using a Transient Directing Group

An Ir-catalyzed reaction of N-benzylideneanilines with functionalized alkenes such as α,β-unsaturated esters gave ortho-substituted benzaldehyde derivatives with a functional group at the remote position after acidic treatment. The present transformation involves deconjugative long-range isomerization (chain-walking) up to 11 times and C-H activation using an imino group as a transient directing group.

Contra-thermodynamic Olefin Isomerization by Chain-Walking Hydroboration and Dehydroboration

We report a dehydroboration process that can be coupled with chain-walking hydroboration to create a one-pot, contra-thermodynamic, short- or long-range isomerization of internal olefins to terminal olefins. This dehydroboration occurs by a sequence comprising activation with a nucleophile, iodination, and base-promoted elimination. The isomerization proceeds at room temperature without the need for a fluoride base, and the substrate scope of this isomerization is expanded over those of previous isomerizations we have reported with silanes.

Hydroboration of carbon dioxide with catechol- and pinacolborane using an Ir–CNP* pincer complex. Water influence on the catalytic activity

Lutidine-derived CNP*–Ir complexes catalyze the hydroboration of CO₂ to methoxyborane and formoxyborane in the presence of small amounts of water.

Dehydrogenative borylation: the dark horse in metal-catalyzed hydroborations and diborations?

Metal-catalyzed hydroborations and diborations frequently give “unwanted” side products arising from a competing dehydrogenative borylation reaction. While catalyst development initially focused on avoiding this “deleterious” pathway, fine tuning of a catalyst system could provide an efficient method to generate unsaturated alkenylboronate esters, synthetically valuable synthons for the Suzuki-Miyaura cross-coupling reaction. The aim of this review is to highlight the history and development of the dehydrogenative borylation reaction in the metal-catalyzed synthesis of alkenylboronate esters.

Promotion of selective pathways in isomerizing functionalization of plant oils by rigid framework substituents

The 1,2-(CH2 P(1-adamantyl)2 )2 C6 H4 (dadpx) coordinated palladium complex [(dadpx)Pd(OTf)2 ] (1) is a catalyst precursor for the isomerizing methoxycarbonylation of the internal double bond of methyl oleate, with an unprecedented selectivity (96 %) for the linear diester 1,19-dimethyl nonadecanedioate. Rapid formation of the catalytically active solvent-coordinated hydride species [(dadpx)PdH(MeOH)](+) (3-MeOH) is evidenced by NMR spectroscopy, and further isolation and X-ray crystal structure analysis of [(dadpx)PdH(PPh3 )](+) (3-PPh3 ). DFT calculations of key steps of the catalytic cycle unravel methanolysis as the decisive step for enhanced selectivity and the influence of the rigid adamantyl framework on this step by destabilization of transition states of unselective pathways.

Homogeneous catalysis for the conversion of biomass and biomass-derived platform chemicals

This perspective highlights the importance of homogeneous catalysis in the selective and efficient transformation of various types of biomass and platform chemicals to useful chemicals.