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In this paper, we disclose a novel strategy for the phosphine-catalyzed cycloaddition/SN2 substitution domino reaction, giving functionalized O-bridged benzoazepine and benzoxazepine derivatives in moderate to good yields. Changing the N-H protecting group of ortho-aminotrifluoroacetophenone derivatives gave different bridged-ring products in one step. [ABSTRACT FROM AUTHOR]

A new zwitterion generated from different electron-deficient alkenes and phosphines has been designed and its reactivity was explored. We demonstrated that this new zwitterion directed a novel [2+1+2] cycloaddition reaction between vinylpyridines and isatin-derived electron-deficient alkenes, affording spirocyclopenteneoxindole derivatives containing three stereocenters in moderate to good yields with good diastereoselectivities. A plausible mechanism has been proposed relying on preliminary mechanistic investigations and supported by theoretical calculations. [ABSTRACT FROM AUTHOR]

Catalytic asymmetric [3+2] cycloadditions of C,N-cyclic azomethine imines with δ-substituted allenoates have been developed in the presence of ( S)-Me-f-KetalPhos, affording functionalized tetrahydroquinoline frameworks in good yields with high diastereo- and good enantioselectivities under mild condition. The substrate scope has been also examined. This is the first time that δ-substituted allenoates have been applied as a δ,γ-CC bond participated C2 synthon in asymmetric synthesis. [ABSTRACT FROM AUTHOR]

The first highly enantioselective formal [4+2] tandem cyclizations between isatylidenemalononitriles and activated dienes catalyzed by bifunctional chiral phosphine catalysts have been developed, yielding multistereogenic spirocyclic oxindoles in high yields and excellent optical purity. This reaction is accomplished via a tandem Rauhut-Currier/Michael/Rauhut-Currier reaction sequence. [ABSTRACT FROM AUTHOR]

A novel phosphine-promoted intramolecular cyclization of dicyclopropenones 1 has been described in this contribution. A variety of 2,3-dihydro-1 H-indene-4,6-diol derivatives 2 and hexahydropentalen-2-one derivatives 3 were obtained selectively in moderate to good yields under mild conditions through different phosphine-promoted reactions. [ABSTRACT FROM AUTHOR]

A novel phosphine-catalyzed highly diastereoselective [3+2] cycloaddition of isatin derived α,β-unsaturated ketones with α-allenic ester has been developed. [ABSTRACT FROM AUTHOR]

Abstract: Cyclization reactions of ethyl 2-(2-hydroxyaryl)-2-oxoacetates with ethyl 2,3-butadienoate and allenylsulfone proceeded smoothly in the presence of tertiary phosphine and sodium p-toluenesulfinate (SPTS) to give the corresponding quaternary carbon centered chromans in moderate to good yields under mild conditions, which provides an alternative efficient approach for the synthesis of biologically active chroman products. [Copyright &y& Elsevier]

The title cyclization is accomplished via a tandem Rauhut-Currier/Michael/Rauhut-Currrier reaction sequence to give spirocyclic oxindoles in high yields along with excellent enantio- and diastereoselectivities. [ABSTRACT FROM AUTHOR]

in the presence of chiral imidazoline-phosphine ligands [ABSTRACT FROM AUTHOR]

The SBIP-catalyzed reaction of benzofuranone alkene (I) with allenes (II) affords γ-addition [3 + 2] cycloadducts (III) with high enantioselectivity, whilst the reaction with allenes (IV) gives rise to α-addition [3 + 2] cycloadducts (V). [ABSTRACT FROM AUTHOR]

Title compounds are regioselectively synthesized by this new phosphine-catalyzed [4 + 1] annulation of Morita-Baylis-Hillman carbonates with oxindole-derived α,β-unsaturated imines. [ABSTRACT FROM AUTHOR]