Abstract Metal-free β- and Z-selective hydrocyanation of terminal ynamides using TMSCN and TBAF is described. The transformation proceeds with excellent regio- and stereoselectivity, delivering exclusively Z-configured tertiary enamides. Treatment with TMSOTf promotes clean Z to E isomerization.…
Abstract Over the last few decades, allenes have evolved from objects of curiosity to central elements of organic synthesis. Among them, N-allenamides, allenes featuring an electron-withdrawing group on the nitrogen, stand out for their great stability and versatility. Their unique reactivity has…
ABSTRACT A totally controlled regiodivergent azidation of activated N-allenamides is presented. Using TMSN3/TBAF, β-azidation of N-allenamides occurs exclusively, yielding vinyl azides. Conversely, employing a TFA/TMSN3 mixture results solely in the formation of γ-azides. A subsequent formal…
Abstract Herein, we report the first visible-light-induced strategy for the rapid synthesis of densely functionalized α- and γ-phosphorylated β-sulfonyl enamines in a regio- and stereoselective fashion from N-sulfonyl allenamides and H-phosphine oxides. The transformation displays a broad…
Abstract Strigolactones exhibit dual functionality as regulators of plant architecture and signaling molecules in the rhizosphere. The important model crop rice exudes a blend of different strigolactones from its roots. Here, we identify the inaugural noncanonical strigolactone, 4-oxo-methyl…
Abstract A method for the construction of trifluorinated-5-methylenepyrrolidinone is reported. This strategy combines an acid-catalyzed two-carbon homologation process between ynamides and aldehydes, providing CF3-substituted dienes followed by a metal-free domino…
Abstract We developed a chemoselective metal-free access for the 1,2- and 2,3-semireduction of CF3-N-allenamides. The enamide functionality of CF3-substituted N-allenamides could be efficiently reduced by Et3SiH/BF3·OEt2 in total regioselectivity and good stereoselectivity, whereas DBU promoted the…
Abstract Specialized metabolite (SM) diversification is a core process to plants' adaptation to diverse ecological niches. Here, we implemented a computational mass spectrometry–based metabolomics approach to exploring SM diversification in tissues of 20 species covering Nicotiana phylogenetics…
Abstract Upon treatment with TBAF, CF3-substituted N-allenamides were transformed into γ-sultams. Cyclic sulfonamides bearing an ene-gem-difluorinated tether could be obtained by addition of acetic acid to the ammonium salt whereas TBAF alone provided the correspondingtrifluorinated ethyl sultams.…
Abstract We report herein a domino reaction to construct 2-amido-5-fluoropyrroles from CF3-substituted N-allenamides. The in situ generated gem-difluorinated ene-ynamides derived from CF3-substituted N-allenamides, when subjected to silver catalysis with a primary amine, undergo simultaneous…
Abstract The two-faced reactivity of N-allenamides allows regio-and stereo-controlled functionalization on the a-, b- and γ-positions of the nitrogen atom. The contingency to obtain either proximal or distal adducts, makes those substrates essential for the construction of complex heterocyclic…
Abstract Strigolactones (SLs) are plant hormones exuded in the rhizosphere with a signaling role for the development of arbuscular mycorrhizal (AM) fungi and as stimulants of seed germination of the parasitic weeds Orobanche, Phelipanche, and Striga, the most threatening weeds of major crops…
Abstract The synthesis of natural products containing eight-membered heterocycles has proved to be highly challenging. In this contribution, an environmentally benign synthesis of benzo-1,5 dioxocines via ynamides is reported. A new class of ynamides was prepared by using a green and mild synthetic…
Abstract The first synthesis of gem-difluorinated ene–ynamides is presented via deprotonation of trifluoromethylated N-allenamides and δ extrusion of fluorine. These highly reactive building blocks, owing to their dual functional groups, offer a unique entry to difluorinated dienes and to…
Abstract A synthesis of new-to-nature aza-iridoids via ynamides is presented. ZrCl4 proved to be the best acid to perform this transformation. Various ynamides were accommodated, and seco-iridoids could be obtained as well. Aza-iridoids were infiltrated into leaves of Scrophularia Nodosa, an…
Abstract N-Allenamides, substituted by an ester at the γ-position, were obtained through addition of terminal ynamides with ethyl diazoacetate under copper catalysis for the first time. Regio- and stereoselective hydroamination of those activated N-allenamides provided exclusively E-configured…
Abstract A copper-mediated coupling reaction between ynamides and diazo-compounds to produce N -allenamides is reported for the first time. This method enables facile and rapid access to terminal N -allenamides by using commercially available TMS-diazomethane with wide functional group…
Abstract The significance of molecules containing difluoromethyl groups is driven by their potential applications in pharmaceutical and agrochemical science. Methods for the incorporation of lightly fluorinated groups such as CF2H have been less well developed. Here we report the use of…
Abstract N-Acyliminium ions generated from enamidyl vinyl ketones provided cyclopentenoid-fused diazepines diastereoselectively using BF3·Et2O in one pot through a domino N-acyliminium ion trapping/Nazarov reaction, simultaneously generating three new stereogenic centers. The particular structural…
