Transition-metal-free allylation of 2-azaallyls with allyl ethers through polar and radical mechanisms

Allylation of nucleophiles with highly reactive electrophiles like allyl halides can be conducted without metal catalysts. Less reactive electrophiles, such as allyl esters and carbonates, usually require a transition metal catalyst to facilitate the allylation. Herein, we report a unique transition-metal-free allylation strategy with allyl ether electrophiles. Reaction of a host of allyl ethers with 2-azaallyl anions delivers valuable homoallylic amine derivatives (up to 92%), which are significant in the pharmaceutical industry. Interestingly, no deprotonative isomerization or cyclization of the products were observed. The potential synthetic utility and ease of operation is demonstrated by a gram scale telescoped preparation of a homoallylic amine. In addition, mechanistic studies provide insight into these C(sp3)–C(sp3) bond-forming reactions.

Reductive C(sp3)–C(sp3) homo-coupling of benzyl or allyl halides with H2 using a water-soluble electron storage catalyst

Four requirements for the reductive C(sp3)–C(sp3) homo-coupling of benzyl/allyl halides in aqueous solution by using H2 as an electron source are described.

Neodymium-Promoted Highly Selective Carbon–Carbon Double Bond Formation of Ketones with Allyl Halides in the Presence of Diethyl Phosphite

The carbon–carbon double bond formation via neodymium-mediated Barbier-type reaction of ketones and allyl halides in the presence of diethyl phosphite is reported for the first time. The reaction is highly α-regioselective and was conveniently carried out under mild conditions in a one-pot fashion. From a synthetic point of view, a series of conjugated alkenes were obtained in moderate to good yields in this one-pot reaction with feasible reaction conditions.

Mechanistic Investigation of Rh(I)-Catalyzed Asymmetric Suzuki-Miyaura Coupling with Racemic Allyl Halides

A mechanism for Rh(I)-catalyzed asymmetric Suzuki-Miyaura coupling with racemic allyl halides is proposed based on a combination of experimental studies and quantum chemical calculations. <br>

Mechanistic Investigation of Rh(I)-Catalyzed Asymmetric Suzuki-Miyaura Coupling with Racemic Allyl Halides

A mechanism for Rh(I)-catalyzed asymmetric Suzuki-Miyaura coupling with racemic allyl halides is proposed based on a combination of experimental studies and quantum chemical calculations. <br>

Enantiomerically enriched tetrahydropyridine allyl chlorides

Enantiomerically enriched allyl halides are rare due to their configurational lability. Stable piperidine-based allyl chloride enantiomers can be produced via kinetic resolution, and undergo highly enantiospecific catalyst-free substitutions.

Visible-light-mediated Barbier allylation of aldehydes and ketones via dual titanium and photoredox catalysis

This study reports a photocatalytic Barbier-type allylation of various aldehydes and ketones with allyl halides for the synthesis of homoallylic alcohols driven by dual titanium and photoredox catalysis.

Enantiomerically Enriched Tetrahydropyridine Allyl Chlorides

Enantiomerically enriched allyl halides are rare due to their configurational lability. Here we report stable piperidine-based allyl chloride enantiomers. These allyl chlorides can be produced via resolution, and undergo highly enantiospecific catalyst-free substitution reactions with C, N, O and S-based nucleophiles. Deuterium-labelled chloro-tetrahydropyridine, selectively prepared using the H/D primary kinetic isotope effect, and DFT calculations were used to investigate the mechanisms of the reactions. The allyl chlorides may also serve as valuable mechanistic tools for probing stereoselective reaction pathways.