A new strategy to construct allylamines through reductive alkenylation of secondary amides with enamines is reported. The method features the use of trifluoromethanesulfonic anhydride as an activation reagent of amides, and enamines as unconventional alkenylation reagents. In this manner, enamines serve as surrogates of alkene carbanions instead of the classical enolates equivalents. A possible mechanism involving a Hoffmann-like elimination of the amine-borane complex intermediate is proposed.

A direct transformation of secondary amides into a-branched ketones with enamines as soft alkylation reagents was developed. In this reaction, enamines serve as surrogates of alkyl carbanions, rather than the conventional enolates equivalents in the Stork's reactions, which allowed for the easy introduction of alkyl groups with electrophilic functional groups. In the presence of 4 Å molecular sieves, the method can be extended to the one-pot coupling of secondary amides with aldehydes to yield ketones.

Based on the Tf2O‐mediated intermolecular reaction of secondary amides with enamines derived from ketones, a novel approach to β‐enaminones has been developed. The reaction is widely functional group tolerant and highly chemoselective. In the presence of 4 Å molecular sieves, the method can be extended to the one‐pot condensation of secondary amides with ketones for NH β‐enaminones synthesis.

Oxygen is an essential substance for plants, and adequate oxygen supply is necessary for plant growth and developments. As one of the major abiotic threats to plants, frequent floods could lead to oxygen deficiency in the rhizosphere. Therefore, it is important to understand the response and adaptive mechanisms of plants to rhizosphere oxygen concentration for crop productions and breeding of resistant varieties. This review shed light on the impacts of rhizosphere oxygen contents on plants from multiple perspectives. We also demonstrated the injury and acclimations caused by oxygen deficiency and the mechanism of low-oxygen signaling. We finally summarized methods to avoid oxygen deficit and prospect of further studies.