A review. Transition metal catalyzed decarboxylative allylations, benzylations, and interceptive allylations are reviewed.

Two natural auxins, phenylacetic acid (PAA) and indole-3-acetic acid (IAA), play crucial roles in plant growth and development. One route of IAA biosynthesis uses the glucosinolate intermediate indole-3-acetaldoxime (IAOx) as a precursor, which is thought to occur only in glucosinolate-producing plants in Brassicales. A recent study showed that overproducing phenylacetaldoxime (PAOx) in Arabidopsis increases PAA production. However, it remains unknown whether this increased PAA resulted from hydrolysis of PAOx-derived benzyl glucosinolate or, like IAOx-derived IAA, is directly converted from PAOx. If glucosinolate hydrolysis is not required, aldoxime-derived auxin biosynthesis may occur beyond Brassicales.To better understand aldoxime-derived auxin biosynthesis, we conducted an isotopelabelled aldoxime feeding assay using an Arabidopsis glucosinolate-deficient mutant sur1 and maize, and transcriptomics analysis.Our study demonstrated that the conversion of PAOx to PAA does not require glucosinolates in Arabidopsis. Furthermore, maize produces PAA and IAA from PAOx and IAOx, respectively, indicating that aldoxime-derived auxin biosynthesis also occurs in maize.Considering that aldoxime production occurs widely in the plant kingdom, aldoximederived auxin biosynthesis is likely to be more widespread than originally believed. A genomewide transcriptomics study using PAOx-overproduction plants identified complex metabolic networks among IAA, PAA, phenylpropanoid and tryptophan metabolism.

Allyl nitroacetates undergo decarboxylative allylation to provide tertiary nitroalkanes in high yield. Moreover, the transformations are complete within several minutes under ambient conditions. High yields result because O-allylation of the intermediate nitronates, which is typically problematic, is reversible under conditions of the decarboxylative allylation process. Lastly, the preparation of substrate allyl nitroacetates by tandem Knoevenagel/Diels-Alder sequences allows the facile synthesis of relatively complex substrates that undergo diastereoselective decarboxylative allylation.

Polyprenylated acylphloroglucinols (PPAPs) are structurally complex natural products with promising biological activities. Herein, we present a biosynthesis-inspired, diversity-oriented synthesis approach for rapid construction of PPAP analogs via double decarboxylative allylation (DcA) of acylphloroglucinol scaffolds to access allyl-desoxyhumulones followed by dearomative conjunctive allylic alkylation (DCAA).

A new method for allylic alkylation of a variety of relatively non-stabilized carbon nucleophiles is described herein. In this process of “deacylative allylation” the coupling partners, an allylic alcohol and a ketone pronucleophile, undergo in situ retro-Claisen activation to generate an allylic acetate and a carbanion. In the presence of palladium, these reactive intermediates undergo catalytic coupling to form a new C–C bond. In comparision to unimolecular decarboxylative allylation, a commonly utilized method for allylation of carbon anions, deacylative allylation is an intermolecular process. Moreover, deacylative allylation allows the direct coupling of readily available allylic alcohols. Lastly, the full utility of deacylative allylation is demonstrated by the rapid construction of a variety 1,6-heptadienes via 3-component couplings.