Herein we report the metal-free diastereoselective frustrated Lewis pair (FLP)-catalyzed hydrogenation of azaMorita−Baylis−Hillman (aza-MBH) adducts, accessing a diverse range of stereodefined β-amino acid derivatives in excellent isolated yields (28 examples, 89% average yield, up to 90:10 d.r.). Furthermore, sequential organo-FLP catalysis has been developed. An initial organocatalyzed aza-MB...

The mechanistic analysis of catalyst-controlled regiodivergent aza-Morita-Baylis-Hillman reactions vinylcyclopentenone is described. DABCO-catalyzed reaction gives the α-adduct exclusively (red reaction) and DMAP-catalyzed produces γ-adduct selectively (blue reaction). revealed that rate-determining step (RDS) α-selective Mannich-type C−C bond formation step, whereas RDS γ-selective seems to be...

The selective hydrogenation of benzofurans in the presence a heterogeneous non-noble metal catalyst is reported. developed optimal catalytic material consists cobalt-cobalt oxide core–shell nanoparticles supported on silica, which has been prepared by immobilization and pyrolysis cobalt-DABCO-citric acid complex silica under argon at 800 °C. This novel allows for simple functionalized to 2,3-di...

Addition of N-ylides derived from DABCO to chalconimines takes place through a Michael addition-cyclization pathway to afford fused cyanopyrroles and/or spirocyclopropanes. The product profile depends heavily on the nature of chalconimines. While 6-membered cyclic chalconimines provide a mixture of pyrrole and spirocyclopropane, 5-membered chalconimines furnish exclusively spirocyclopropane. Cy...

The 1,6-conjugate addition of nucleophiles to dienyl diketones produces either cyclopentenone or 2H-pyran products with high selectivity through either Nazarov (4π) or 6π electrocyclization, respectively. The outcome of the reaction is dependent upon the nature of the nucleophile used. Nucleophiles that are anionic or easily deprotonated exclusively produce cyclopentenones via Nazarov cyclizati...

The addition of 1,4-diazabicyclo-[2,2,2]octane (DABCO) (100 mM) or 1,2-dihydroxybenzene-3,5-disulfonic acid (Tiron) (1 mM) to a reaction mixture containing 10 mM linoleic acid (LA), 20% EtOH, and 135 microM dehydroascorbic acid (DHA) as a catalyst suppressed LA peroxidation, but the addition of mannitol (approximately 100 mM), uric acid (100 microM), and catalase (6.5 units) did not. DHA or 2,3...

The regioselectivity of copper(I)-catalyzed synthesis of 1,2,3-triazoles in dabco-based ionic liquids has been investigated at the DFT level using a supermolecular approach. The analysis of the theoretical results shows that the coordination ability of the ionic liquid (IL) anion to copper(I) catalyst and to all the other species containing the copper (intermediates and transition states) can s...

A direct β-coupling of cyclic ketones with imines has been accomplished via the synergistic combination of photoredox catalysis and organocatalysis. Transient β-enaminyl radicals derived from ketones via enamine and oxidative photoredox catalysis readily combine with persistent α-amino radicals in a highly selective hetero radical-radical coupling. This novel pathway to γ-aminoketones is predic...

A one-pot preparation of pyridyl isothiocyanates (ITCs) from their corresponding amines has been developed. This method involves aqueous iron(III) chloride-mediated desulfurization of a dithiocarbamate salt that is generated in situ by treatment of an amine with carbon disulfide in the present of DABCO or sodium hydride. The choice of base is of decisive importance for the formation of the dith...