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A new and efficient strategy for the stereoselective synthesis of tetrahydropyridino- and deazepanopyrrolo[1,2- c ]imidazolidines has been developed. Annulation of acylethynylpyrroles with six- and seven-membered cyclic imines (MeCN/THF, 20–25 °C, 24–72 h) leads to tetrahydropyrrolo[1′,2′:3,4]imidazo[1,2- a ]pyridines and hexahydropyrrolo[1′,2′:3,4]imidazo[1,2- a ]azepines with (E)-acylethenyl moiety in 28–96% yields. [ABSTRACT FROM AUTHOR]

Available pyrrolylalkynones with tetrahydroindolyl, cycloalkanopyrrolyl, and dihydrobenzo[g]indolyl moieties, acylethynylcycloalka[b]pyrroles, are readily annulated with Δ1-pyrrolines (MeCN/THF, 70 °C, 8 h) to afford a series of novel pyrrolo[1′,2′:2,3]imidazo[1,5-a]indoles and cyclohepta[4,5]pyrrolo[1,2-c]pyrrolo[1,2-a]imidazoles functionalized with an acylethenyl group in up to an 81% yield. This original synthetic approach contributes to the arsenal of chemical methods promoting drug discovery. Photophysical studies show that some of the synthesized compounds, e.g., benzo[g]pyrroloimidazoindoles, are prospective candidates for TADF emitters of OLED. [ABSTRACT FROM AUTHOR]

The ring-opening/functionalization of 1-pyrrolines by cyano-acetylenes or acetylenic ketones (20–80 °C, MeCN, H2 O) affords δ-keto aminoacrylonitriles and δ-keto aminoenones, mostly as the Z -isomers, in up to 85% yields. The synthesis involves C(2)–N bond cleavage in the intermediate hemiaminal resulting from the intermediate 1,3(4)-dipolar 1-pyrroline/acetylene complexes and water. [ABSTRACT FROM AUTHOR]

Electron-deficient propargylic alcohols (EWG = CN, C(O)Ph, CO2Me, C(O)NH2) under catalyst-free mild conditions are annulated with Δ1-pyrrolines to afford functionalized hexahydropyrrolo[ 2,1-b]oxazoles, mostly in 19–93 % yield. The synthesis is stereoselective with respect to disposition of functionalized ethenyl group relative to the condensed heterocyclic system thus formed in most cases. This methodology provides a simple one-pot access to a novel family of synthetically and pharmaceutically prospective. [ABSTRACT FROM AUTHOR]

The catalyst- and solvent-free reaction between bis(fluoroalkyl) phosphonates and aldimines occurs under mild conditions (20–22 °C, 0.25–4 h) to afford a new family of α-amino polyfluoroalkylphosphonates in up to quantitative yields. [ABSTRACT FROM AUTHOR]

Chemoselective and atom-economical methods for the synthesis of ferrocene diethenyl ethers have been developed via direct base-catalyzed addition of 1,1′-bis(hydroxymethyl)ferrocene to various acetylenes. This ferrocene diol has been shown to be capable of adding to acetylene (KOH/DMSO, 70–80 °C, 1–3 h), propyne (KOH/DMSO, 70 °C, 12 h), phenylethyne (KOH/DMSO, 20–25 °C, 48 h), alkylpropiolates (DABCO, 10 mol%/CH2 Cl2 , 20–25 °C, 0.5 h), and acylacetylenes (DABCO, 1 mol%/CH2 Cl2 , 20–25 °C, 0.5 h) to afford the corresponding diethenyl ethers in 73–98% yields. [ABSTRACT FROM AUTHOR]

The reaction of 3 H -indoles with tertiary propargylic alcohols to give functionalized dihydrooxazolo[3,2- a ]indoles in good to excellent yields has been developed. This metal- and solvent-free, one-pot tandem assembly proceeds under mild conditions (22–60 °C) and is regio- and stereoselective: either the Z - or E -isomers (relative to the double bond) are alternatively formed depending on other functionalized substituents on the propargylic alcohols. [ABSTRACT FROM AUTHOR]

The original four-component reaction between secondary phosphines, primary amines, aldehydes, and elemental sulfur or selenium occurs chemoselectively under mild conditions (60 °C, benzene, 3–9 h) to afford the hitherto unknown functionalized α-aminophosphine sulfides and selenides in good to excellent yields. [ABSTRACT FROM AUTHOR]

ABSTRACT Earlier unknown S-[1-(organosulfanyl)ethyl]- and S-[1-(organoselenyl)ethyl] dithiophosphinates were synthesized in 85-97% yields by regioselective addition of dithiophosphinic acids to diverse vinyl sulfides and selenides under mild conditions (ambient temperature, Et2O, 3 h). [ABSTRACT FROM AUTHOR]

A one-pot, atom-economic, metal- and halogen-free synthesis of functional triphosphines with nitrogen and (or) oxygen atoms as additional weaker coordinating sites (new hemilabile ligands) through exhaustive addition of secondary phosphines to available trivinyl ethers of aminotriols and triols has been developed. The reaction proceeds under free-radical conditions (UV irradiation or AIBN, with 3:1 reactant molar ratio) to give chemo- and regioselectively anti-Markovnikov triadducts to all three vinyloxy groups in good to excellent yields. [ABSTRACT FROM AUTHOR]

Secondary phosphines and phosphine chalcogenides add to the divinyl ether of α,ω-alkane diols regio- and chemoselectively under free-radical conditions (UV irradiation or AIBN, 2:1 reactants molar ratio) to give anti-Markovnikov diadducts in good to excellent yields (65-98%). [ABSTRACT FROM AUTHOR]

The reactions of secondary phosphine ?halcogenides with vinyloxyalkylamines proceed chemoselectively in triethylamine- carbon tetrachloride under mild conditions to give the corresponding phosphino?halcogen?ic amides bearing vinyloxy moieties in 78-95% yields. [ABSTRACT FROM AUTHOR]

A family of previously unknown phosphinodiselenoic esters containing a selenoacetal moiety, R² 2P(=Se)SeCH(Me)OR¹ (R¹, R² = alkyl, aryl, etc.), were synthesized by means of a three-component reaction between the elemental selenium and the corresponding vinyl ether and secondary phosphine. The reaction proceeds readily in 1,4-dioxane at 90 °C for 1-1.5 hours and gives the phosphinodiselenoic esters quantitatively and in an entirely atomeconomic manner. The reaction proceeds through electrophilic addition to the electron-rich double bond of the phosphinodiselenoic acids generated in situ. [ABSTRACT FROM AUTHOR]

Abstract: First bis(diorganothiophosphinyl)selenides, (R2P=S)2Se, have been synthesized in 74–86% yield by the chemoselective interaction of secondary phosphine sulfides with elemental selenium (1:1 molar ratio, 100°C, 3h, 1,4-dioxane); the alternative bis(diorganoselenophosphinyl)sulfides, (R2P=Se)2S, are not formed under these conditions. [Copyright &y& Elsevier]

Acylethynylpyrroles undergo facile (rt, MeCN or MeOH, 24-72 h) catalyst-free annulation with 1-pyrrolines to afford acylmethylenetetrahydrodipyrrolo[1,2- a :1',2'- c ]imidazoles in up to 93% yield and 90% E -stereoselectivity of the olefin moiety.