A next generation total synthesis of vancomycin aglycon is detailed that was achieved in 17 steps (longest linear sequence, LLS) from the constituent amino acid subunits with kineticallycontrolled diastereoselective introduction of all three elements of atropisomerism. In addition to new syntheses of three of the seven amino acid subunits, highlights of the approach include a ligand-controlled atroposelective one-pot Miyaura borylation-Suzuki coupling sequence for introduction of the AB biaryl axis of chirality (>20:1 dr), an essentially instantaneous and scalable macrolactamization of the AB ring system nearly free of competitive epimerization (>30:1 dr), and two room temperature atroposelective intramolecular S N Ar cyclizations for sequential CD (8:1 dr) and DE ring closures (14:1 dr) that benefit from both preorganization by the preformed AB ring system and subtle substituent effects. Combined with a protecting group free two-step enzymatic glycosylation of vancomycin aglycon, this provides a 19-step total synthesis of vancomycin. The approach paves the way for large scale synthetic preparation of pocket modified vancomycin analogues that directly address the underlying mechanism of resistance to vancomycin.

As an important vegetable crop of the legume family, cowpea (Vigna unguiculata L.) is grown widely for its tender pod with good taste and nutrition. The purple cowpea pods attract more attention mainly for the eye-catching color and healthpromoting ingredients. Initially, large quantities of two major anthocyanins (delphinidin 3-O-glucoside and cyanidin 3-O-glucoside) and nine kinds of flavonoids (most are quercetin-based flavonol glycosides) were separated and identified from purple cowpea pod by ultra-high performance liquid chromatography coupled with quadrupole Orbitrap high-resolution mass spectrometry. To study them systematically, two representative cowpea cultivars with a drastic difference in anthocyanin accumulation were further analyzed by the integration of metabolomics and transcriptomics. A total of 56 differentially accumulated metabolites and 4142 differentially expressed genes were identified, respectively. On the basis of the comprehensive analysis of multiomic data, it was shown that VuMYB90-1, VuMYB90-2, VuMYB90-3, VuCPC, VuMYB4, and endogenous bHLH and WD40 proteins coordinately control anthocyanin and flavonoid accumulation via transcriptional regulation of structural genes in purple cowpea pod.

A concise synthesis of peptides that contain E- or Z-dehydroisoleucine (ΔIle) residues is reported. The key reaction is an unusual anti dehydration of β-tert-hydroxy amino acid derivatives that is mediated by the Martin sulfurane. A subsequent tandem Staudinger reduction-O → N acyl transfer process forges an amide bond to the ΔIle residue with minimal E/Z alkene isomerization. Density functional calculations attribute the stereospecific dehydration to a highly asynchronous E2 anti process.

Microwave-promoted iminyl radical cyclizations can be terminated by trapping with TEMPO, affording functionalized adducts. The use of alkynes as radical acceptors delivers a range of 2-acylpyrroles in good yields. Toxic and hazardous reagents, which are frequently employed in radical reactions, are not required. The O-phenyl oxime ether substrates are constructed in a single step from readily available ketones.

O-Phenyloximes tethered to alkenes undergo 5-exo-trig iminyl radical cyclizations upon microwave irradiation. Trapping of the resulting cyclic radicals results in C–C, C–N, C–O, C–S, or C–X bond formation. Allylic sulfides undergo a tandem cyclization–thiyl radical β-elimination, affording terminal alkenes. The cyclizations exhibit a broad scope, and in some cases they are highly diastereoselective. The pyrroline adducts are versatile intermediates that can be transformed into a range of different species.