The sterically encumbered pyrrolyl KPyr(tBu2) (1-K, Pyr(tBu2) = 2,5-(Me3C)2C4H2N) reacts with PCl3, (iPr)2PCl and Ph2PCl exclusively at the C3-position to yield a series of phosphine-substituted pyrroles HPyr(tBu2R) (R = PCl2 (2-H), (iPr)2P (4-H) and Ph2P (5-H)). Pyrrole 2-H can further be functionalized with MeLi (3 equiv.) to yield LiPyr(tBu2PMe2) (3-Li). The coordination chemistry of these p...

Easy accessible isoxazol-5(4 H )-ones are useful precursors of heterocycles. In this context we report the ruthenium-catalyzed transformation 4-alkenyl-substituted isoxazol-5-ones to afford 1 -pyrrole derivatives. The operative conditions were proven be effective also on cyclohexane-fused isoxazolones giving 4,5,6,7-tetrahydroindoles. Reactions, which allow access tri-and tetra-substituted pyrr...

A base-catalyzed selective cycloisomerization of 3-aza-1,5-enynes is developed. This transformation provides a facile access to highly functionalized 2-azabicyclo[3.2.0]hept-2-enes and sulfonyl vinyl-substituted pyrroles. The chemoselectivity was controlled by the substituent pattern of the substrates.

Pyrrolo[2,1-f][1,2,4]triazin-4(3H)-ones 12 have been easily prepared via nucleophile-induced rearrangement of pyrrolooxadiazines 11 and regioselective intramolecular cyclization of 1,2-biscarbamoyl-substituted 1H-pyrroles 10. In this work, we demonstrated that the described synthetic approaches can be considered to be more facile and practical than previously reported procedures.

gem-Dialkylthio vinylallenes were obtained for the first time and applied to the divergent synthesis of fully-substituted pyrroles and thiophenes by domino cyclizations. These two cyclization pathways were regulated by alkylthio groups. Plausible reaction mechanisms were presented and supported by DFT calculations. An unprecedented metal-free carbothiolation was discovered in the formation of t...

In this paper, a simple and highly efficient ruthenium-catalyzed direct C3 alkylation of indoles with various α,β-unsaturated ketones without chelation assistance has been developed. This novel C-H activation methodology exhibits a broad substrate scope such as different substituted indoles, pyrroles, and other azoles. Further synthetic applications of the alkylation products can lead to more a...

Various tetrasubstituted pyrroles/pyrazoles have been prepared from nitro-substituted 1,3-enynes with aromatic amines/hydrazines via a copper-catalyzed cascade aza-Michael addition, cyclization and aromatization at room temperature. This protocol is also effective for the synthesis of tetrasubstituted pyrazoles in high yields.

A cyclization reaction between enamides and alkynes catalyzed by palladium(II) acetate is described. In this method, the molecular oxygen serves as an efficient oxidant for the Pd(II)/Pd(0) catalytic cycle. The simple reaction conditions permit this methodology to be used as a general tool for the preparation of multi-substituted pyrroles.

Pyrrolyl and indolyl substituted allenylidene complexes of ruthenium have been prepared from the trapping of cationic trans-[Cl(dppm)(2)Ru=C=C=C=CH(2)](+) with various pyrroles or N-methylindole. The reaction is rationalized as involving regioselective attack of the organometallic electrophile on the electron-rich heterocycle followed by proton migration to the terminal =CH(2) entity of the int...