Enantioselective Synthesis of Aminals Via Nickel-Catalyzed Hydroamination of 2-Azadienes with Indoles and N-Heterocycles.

New methods for the enantioselective synthesis of N-alkylated indoles and their derivatives are of great interest because indoles are pivotal structural elements in biologically active molecules and natural products. They are also versatile intermediates in organic synthesis. Among well-established asymmetric hydroamination methods, the asymmetric hydroamination with indole-based substrates is a formidable challenge.

Collective Syntheses of Alkaloids Based on a Chirality-Tunable Structure Unit.

A novel strategy based on a common intermediate bearing a chirality-tunable structure unit for the collective syntheses of corynantheine-type and heteroyohimbine-type alkaloids has been developed. Key transformations of the synthetic strategy are a sequential nucleophilic C-N bond formation/Mannich-type cyclization to construct the highly functional C/D rings, a stereocontrolled introduction of the C15 and C20 chiral centers based on the chirality-tunable structure unit, and an amine-directed addition of MeAl to construct the C18 methyl group.

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.