Results 171 to 180 of about 1,879 (233)

Design, Synthesis and Cholinesterase Inhibitory Activity of New Dispiro Pyrrolidine Derivatives

Social Science Research Network, 2022
A series of new dispiro pyrrolidines were regioselectively synthesised via [3+2]- cycloaddition reactions of 3,5-bis(arylidene)-1-phenylethyl-4-piperidones with azomethine ylides generated in situ from N -methylglycine and appropriate isatin derivatives.
Nadia Mohamed Yusoff, Hasnah Osman, Valentia Katemba, Muhammad Solehin, Abd Ghani, U. Supratman, Mohammad Tasyriq, Cherkaoui Omar, V. Murugaiyah, Xiang Ren, Yvan Six, Mohamad Nurul Azmi   +11 more
semanticscholar   +1 more source

Darstellung und Struktur von Dispiro‐diazaphosphetidinen

Chemische Berichte, 1977
AbstractDurch thermolytische Abspaltung von Fluortrimethylsilan aus den 2,2‐Difluor‐4,4,5,5‐tetrakis‐(trifluormethyl)‐2‐trimethylsilylamino‐1,3,2λ5‐dioxaphospholanen 1 und 2 werden erste Vertreter 3 und 4 von dispirocyclisch angeordneten fünf‐ und viergliedrigen Ringen synthetisiert.
James Andrew Gibson, Gerd‐Volker Röschenthaler, Dietmar Schomburg, William S. Sheldrick   +3 more
openaire   +1 more source

Diastereoselective Construction of Tetrahydro-Dispiro[indolinone-3,2'-pyran-5',4″-pyrazolone] Scaffolds via an Oxa-Michael Cascade [4 + 2] Annulation Reaction.

Journal of Organic Chemistry, 2022
A straightforward metal-free oxa-Michael cascade [4 + 2] annulation reaction was established between isatin-derived Morita-Baylis-Hillman (Is-MBH) alcohols with alkylidene pyrazolones to access structural diverse tetrahydro-dispiro[indolinone-3,2'-pyran ...
Kanduru Lokesh, Nandarapu Kumarswamyreddy, V. Kesavan   +2 more
semanticscholar   +1 more source

Regio- and Stereoselective Synthesis of Dispiro-bisoxindoles via [3+2] Annulation Involving Nitroisatylidene as a Vinylogous Michael Donor.

Organic Letters, 2021
A cascade [3+2] annulation, involving a γ-selective vinylogous Michael addition of nitroalkylideneoxindoles to various electron deficient alkenes followed by an intramolecular Michael addition, provides access to dispiro-bis-oxindoles and spiro-oxindoles.
Chenikkayala Siva Sankara, I. Namboothiri   +1 more
semanticscholar   +1 more source

‘Exploration of photovoltaic behavior of bithiophene-functionalized dispiro-oxepine based hole-transporting materials for efficient perovskite solar cells’

Physica Scripta
Perovskite solar cells (PSCs) have received great attention from researchers due to their superior photovoltaic properties, high efficiency, and low cost.
Arslan Basharat, Raheela Sharafat, Waqar Ali Zahid, Nabeel Shahzad, Muneerah Alomar, Javed Iqbal   +5 more
semanticscholar   +1 more source

Synthesis of dispiro hetero analogs of pyrrolizidine alkaloids

Russian Journal of Organic Chemistry, 2012
Reactions of spiro heterocyclic enamines with 1H-pyrrole-2,3-diones, including those fused at the N–C bond to nitrogen-containing heterocycles, were not studied. We have found that 3-aroyl-1H-pyrrolo[2,1-c][1,4]benzoxazine-1,2,4-triones Ia and Ib react with an equimolar amount of 2′,5′,5′-trimethyl-4′,5′-dihydro-4H-spiro[naphthalene-1,3′-pyrrol]-4-one (
V. V. Konovalova, Yu. V. Shklyaev, A. N. Maslivets   +2 more
openaire   +1 more source

Phosphorus-Nitrogen Compounds: Part 76. Design and Syntheses of Dispiro- and Trispiro(N/N)cyclotriphosphazenes: Conformational and Structural Analyses, Chirality, Electrochemical, Dye-Sensitized Solar Cells, and Bioactivity Studies.

Inorganic Chemistry
The reactions of monospirocyclotriphosphazenes (1 and 2) with N-methyl-1,3-diaminopropane gave unsymmetrical cis-(3 and 5) and trans-(4 and 6) dispirocyclotriphosphazenes.
Reşit Cemaloğlu, Nuran Asmafiliz, Y. Tümer, T. Hökelek, Z. Kılıç, Nejla Nur Çelik, L. Açık, Remziye Güzel, Gülbahar Güzel Erdal   +8 more
semanticscholar   +1 more source

Synthesis of dispiro-orthoester via an acetal oxo-carbenium ion.

Chemical Communications
The first dispiro orthoester via a spiroacetal oxo-carbenium ion is presented. Oxidative dearomatization of phloretic esters results in a bifunctional electrophilic spiroacetal oxo-carbenium ion, which undergoes a double nucleophilic addition by diol ...
Manoj Kumar, Shubham Singh, Parthasarathi Subramanian   +2 more
semanticscholar   +1 more source

Synthesis, Structures, and Optical Properties of Heteroarene-Fused Dispiro Compounds

The Journal of Organic Chemistry, 2010
Novel heteroarene-fused dispiro compounds, dispiro[9H-fluorene-9,5'(6'H)-diindeno[1,2-b:2',1'-d]furan-6',9''-[9H]fluorene] (dsp-DIF), dispiro[9H-fluorene-9,5'(6'H)-diindeno[1,2-b:2',1'-d]thiophene-6',9''-[9H]fluorene] (dsp-DIT), and 11-phenyldispiro[9H-fluorene-9,5'(6'H)-diindeno[1,2-b:2',1'-d]pyrrole-6',9''-[9H]fluorene] (dsp-DIP-Ph) have been ...
Kowada, Toshiyuki, Kuwabara, Toshihisa, Ohe, Kouichi   +2 more
openaire   +2 more sources

A novel entry into a new class of spiroheterocyclic framework: regioselective synthesis of dispiro[oxindole-cyclohexanone]pyrrolidines and dispiro[oxindole-hexahydroindazole]pyrrolidines

Tetrahedron, 2001
Abstract 2,6-Bis(arylmethylidene)cyclohexanones undergo a regioselective 1,3-dipolar cycloaddition reaction with the azomethine ylide derived from isatin and sarcosine by a decarboxylative route affording a series of 1-N-methyl-spiro[2.31]oxindole-spiro[3.211]611-arylmethylidenecyclohexanone-4-aryl-pyrrolidines which were further annulated to give a ...
A Amal Raj, R Raghunathan
openaire   +1 more source