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It is reported herein that by exploiting the commonly shared bicyclic decahydroquinoline motif, a gold-catalyzed enamide-alkyne cycloisomerization reaction is developed to access tricyclic cores in a simple way. These tricyclic cores further serve as an advanced platform for the divergent enantioselective collective total syntheses of five Lycopodium alkaloids, belonging to three different structural types, in a concise and protecting-group-free fashion. The key transformations in the second phase include: 1) a transannular reductive Heck cyclization for installation of the azepane ring in fawcettidine, fawcettimine, and lycoposerramine Q; 2) a domino Mukaiyama hydration/Grob fragmentation process for construction of the ten-membered lactam system in phlegmariurine B; 3) a Fukuyama one-pot protocol for the construction of the 2-pyridone motif in lycoposerramine R. The newly developed strategy is expected to pave the way for the synthesis of other structurally related Lycopodium alkaloids.

A highly efficient strategy of two different types of nitrogen-rich heterocyclic energetic compounds, featuring a single NH-bridge (–NH–) and a fused ring, was demonstrated by virtue of Dimroth rearrangement reactions using 4-amino-5-nitro-1,2,3-triazole as the precursor. Various nitrogen-rich compounds and their salts were prepared via this transformation and fully characterized using multinuclear NMR spectroscopy, IR, elemental analysis, and single crystal X-ray structuring. Their key properties, such as decomposition temperatures, densities, detonation velocities and pressures, and impact sensitivities, were obtained from theoretical calculations or experimental measurements. With different task-specific explosophores, the representative energetic compounds 6b and 18 exhibit great potential as high performance insensitive energetic materials and organic primary explosives, respectively. This work gives the classic Dimroth rearrangement new vitality to access diversified task-specific energetic materials.

Described herein is a novel and efficient copper-catalyzed oxidative phosphonation of α-tert-hydroxylalkenes. This protocol displays a broad scope with good functional group compatibility and gives efficient access to diverse β-oxophosphine oxides from simple allylic alcohols and H-phosphine oxides. The mechanism is proposed to be an unprecedented three-component radical coupling/fragmentation cascade reaction of α-tert-hydroxylalkenes, HP(O)R1R2 and tert-butyl hydroperoxide (TBHP), in which the excess TBHP acts as not only a radical initiator but also a coupling partner.

An enantioselective total synthesis of the natural chroman-sesquiterpenoid (−)-8-epi-chromazonarol has been accomplished by a unique N2H4·H2O promoted highly diastereo-selective oxa-Michael cyclization to construct the central chroman framework and assemble the unusual C8 stereocenter. The other salient feature of the reported synthesis involves a Stille carbonylative cross-coupling reaction to link the aryl stannane 9 and bicyclic triflate 10.

The construction of the ABC tricyclic skeleton of malabanone A with the required 4 stereocenters was accomplished in a concise route starting from R-carvone. The synthesis featured an intramolecular [3 + 2] cycloaddition reaction to assemble its A ring and an intramolecular Diels-Alder reaction to construct its C ring.

The first asymmetric total synthesis of gymnothelignan L has been accomplished in 14 steps with 11.2% overall yield. The synthetic approach features an anti Evans aldol reaction, a diastereoselective methylation, a Suzuki–Miyaura coupling and a bioinspired desymmetric transannular Friedel–Crafts reaction. Notably, the synthesis further demonstrated the biogenetic pathway that dibenzocyclooctene-type lignans are generated from eupomatilone-type lignans.

A strategy for the synthesis of multisubstituted hydrocarbazoles has been developed through (3 + 2)-annulation of p-quinamines and arynes. In this way, new analogs of hydrocarbazoles with quaternary carbon center can be synthesized in satisfactory yield under mild conditions. Furthermore, this (3 + 2)-annulation can be easily scaled-up, and the products can be modified through simple transformation.

An efficient synthesis of complex tetracyclic compounds is developed which relies on a gold(I)-catalyzed tandem 1,2-acyloxy migration/[3 + 2] cycloaddition/Friedel–Crafts type cyclization reaction of linear enynyl esters. The reaction proceeds under extremely mild conditions in good to excellent yields (54%–88%) with a dr value of up to 20 : 1.

A visible-light-mediated radical addition of alkynoates to generate 3-bromocoumarins by using N-bromosuccinimide as the bromo source has been accomplished. This procedure provides a bromo radical addition/spirocyclization/ester migration cascade reaction under very mild reaction conditions without using any catalyst or strong oxidant and does not need high reaction temperature. Furthermore, the reaction can also be enlarged to the gram scale, and the product 3-bromocoumarins can be further applied in the synthesis of complex compounds.

A visible-light promoted single electron oxidation of ether enabled by photoredox catalysis has been accomplished. This procedure initiates a novel radical insertion/cyclization cascade reaction to generate phenanthridines and isoquinolines from easily available isocyanides under mild reaction conditions.

A visible-light-promoted, mild, and direct difunctionalization of alkynoates has been accomplished. This procedure provides a new strategy toward synthesis of the coumarin core structure by photoredox-mediated oxidation to generate the α-oxo radical, which supervenes a domino radical addition/cyclization reaction in moderate to good yields with high regioselectivity at ambient temperature.

A visible-light-promoted, mild, and direct difunctionalization of alkynoates has been accomplished. This procedure provides a new strategy toward synthesis of the coumarin core structure by photoredox-mediated oxidation to generate the α-oxo radical, which supervenes a domino radical addition/cyclization reaction in moderate to good yields with high regioselectivity at ambient temperature.

An effective synthesis of structurally diverse benzazocines was accomplished in good to excellent chemical yields (55-82 %) through a gold(I)-catalyzed cascade reaction involving tandem 1,2-acyloxy shift/[3+2] cycloaddition of terminal 1,9-enynyl esters. The reaction proceeds under extremely mild conditions and represents one of the relatively few transition-metal-catalyzed intramolecular cycloaddition reactions for the synthesis of benzazocines.

Abyssinone-V, 4'-hydroxy-6,3',5'-triprenylisoflavonone, abyssinone-VI and abyssinone-IV were all isolated from the genus erythrina. This study completed the first total synthesis of four natural prenylated flavanoids by using simple and facile approaches. The result of their in vitro antibacterial tests indicated that all of them displayed moderate bacteriostatic activities. The compounds abyssinone-IV and abyssinone-V showed remarkable antibacterial activities. The structures of all new compounds have been confirmed by HRMS, 1 H NMR and 13 C NMR spectra.