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In the catalyzed decarboxylative etherification of propargyl carbonates the gold(I) catalyst shows a distinct σ-acidity and propargyl ethers are furnished.

A gold-catalyzed cyclization of 3-(2′-azidoaryl)-1-arylpropargyl carbonates to generate substituted quinolines via a sequence of 3,3-rearrangement, 6-endo-trig cyclization and denitrogenation has been developed. Similar products could be obtained from 3-aryl-1-(2′-azidoaryl)propargyl carbonates under different gold catalytic conditions via a sequential 6-endo-dig cyclization, denitrogenation, and 1,2-H shift process.

A highly efficient, facile, and mild synthesis of the title compounds is developed from easily available starting materials.

A convenient sequential method for the facile and efficient synthesis of the title compounds (II) and (IV) from easily accessible starting materials is developed under mild conditions.

Homo-Michael addition of Li selenolates to cyclopropyl ketones and subsequent reaction with electrophiles leads to allenyl or alkynyl ketones or furans.

A catalytic ene-like reaction of aldehydes with those vinyl ethers that display the oxygen functionality at the central carbon of an allylic system, e.g., 2-methoxypropene, is discussed in detail. The reaction is promoted by 0.05 equiv. of the 1:1 complex of Yb(fod)3 and acetic acid, and it is forms the centerpiece of our synthesis of chlorovulone II, mitomycinoids and phyllanthocin.

We describe a total synthesis of (±)-chlorovulone II that is 10 steps shorter than the best alternative currently available (nine vs 19 steps). The key event of the synthesis is an aldol addition of the enolate of ethyl acetate into 4-cyclopentene-1,3-dione, a substance that has received little attention as an educt for prostanoid synthesis and for which little is known about carbonyl 1,2-addition with enolates. In addition, we provide chemical and stereochemical details of a route to a key intermediate toward the title compound that involves a carbonyl−ene reaction and a radical addition to an aldehyde carbonyl.

In this paper, we report a novel sequential reaction sequence consisting of a series of processes including Sonogashira coupling, propargyl-allenyl isomerization, [3 + 2] cycloaddition, denitrogenation, and highly selective biradical coupling reaction, providing an efficient synthesis of fused polycyclic pyrrole derivatives. The reaction features one C-C bond and two C-N bonds formed to construct the pyrrole unit, together with two rings efficiently assembled in one stroke.

An interesting sequential reaction involving Pd-catalyzed coupling, propargyl−allenyl isomerization, and Alder−ene cycloaddition is reported, providing a facile synthesis of some not readily available 2,3-dihydrofurans from electron-deficient vinyl or aromatic halides and 1-aryl-prop-2-ynyl 3′-methylbut-2′-enyl ethers.

A novel Pd-catalyzed sequential reaction for the synthesis of fused tricyclic compounds with a dihydrofuran or isobenzofuranone unit was developed.

A series of dicationic porphyrins were found to specifically recognize loop structures of oligodeoxynucleotides, and to selectively oxidize guanine residues upon photo-irradiation at micromolar concentrations. These compounds could, thus, be employed as promising structural probes for specific secondary DNA structures. The production of singlet oxygen ((1)O2) is responsible for the DNA-modification profiles. Both UV-titration and thermal-melting experiments indicate that the strong affinity of the charged porphyrins towards DNA loops is responsible for these molecular-recognition phenomena.