59142-59-5Relevant academic research and scientific papers
Palladium(II)-catalyzed Intermolecular Cascade Cyclization of Methylenecyclopropanes with Aromatic Alkynes: Construction of Spirocyclic Compounds Containing Indene and 1,2-Dihydronaphthalene Moieties
Fang, Wei,Wei, Yin,Shi, Min
supporting information, (2019/05/22)
A palladium(II)-catalyzed intermolecular cascade cyclization of methylenecyclopropanes with aromatic alkynes is reported in this paper. The reaction involves a migratory insertion of alkyne, an intramolecular Heck-type reaction, and β-H elimination, providing a series of spirocyclic compounds containing indene and 1,2-dihydronaphthalene moieties in moderate to excellent yields upon heating.
Enantioselective N-Heterocyclic Carbene Catalyzed Synthesis of Functionalized Indenes
Zhang, Changhe,Lupton, David W.
supporting information, p. 4456 - 4459 (2017/09/11)
An enantioselective NHC (N-heterocyclic carbene) catalyzed synthesis of indenes from bifunctional α,β-unsaturated acyl fluorides and TMS enol ethers has been discovered. The reaction has broad generality (31 examples) and proceeds with high levels of enantioselectivity (most >92:8 er). Mechanistically the reaction likely occurs via a Michael/β-lactonization/decarboxylation sequence. Derivatization studies and limitations are discussed.
Photoinduced C-Br homolysis of 2-bromobenzophenones and Pschorr ring closure of 2-aroylaryl radicals to fluorenones
Moorthy, Jarugu Narasimha,Samanta, Subhas
, p. 9786 - 9789 (2008/03/17)
(Chemical Equation Presented) A variety of diversely substituted 2-aroylaryl radicals, generated by photoinduced homolysis of 2-bromoarylketones, is shown to undergo Pschorr cyclization to yield fluorenones in moderate to excellent yields. The photochemical results illustrate that the substituents in the two phenyl rings of the 2-bromobenzophenone skeleton exert a dramatic influence on the reactivity of the derived 2-aroylaryl radicals. The disubstitution by methoxy groups in the radical ring renders the aryl σ-radical highly electrophilic and unreactive for hydrogen abstraction and cyclization. On the other hand, the substituents in the non-radical ring that strongly stabilize the hydrofluorenyl π-radical, formed subsequent to the attack of the 2-aroylaryl radical on the non-radical ring, promote cyclization to furnish fluorenones in excellent isolated yields.
Synthesis of spiro[isobenzofuran 1(3H),4' piperidines] as potential central nervous system agents
Bauer,Duffy,Hoffman,Klioze,Kosley Jr.,McFadden,Martin,Ong
, p. 1315 - 1324 (2007/10/05)
Synthesis of 1' methyl 3 phenylspiro[isobenzofuran 1(3H),4' piperidine] (7a, HP 365) and the demethyl analogue 9a (HP 505) was prompted by recognition of an aminoalkyl(aryl)isobenzofuran moiety common to the antidepressants talopram (Lu 3-010) and trans 10,11 dihydro 5,10 epoxy 5 [3 (methylamino)propyl] 5H dibenzo[a,d]cyclohepten 11 ol (MK-940). Convenient laboratory synthesis of 7a was provided by lithiation of 2 bromobenzhydryl methyl ether, followed by addition of 1 methyl 4 piperidone and acid catalyzed cyclization. N Dealkylation by standard methods afforded 9a. Synthesis of analogues was stimulated by discovery of marked inhibition of tetrabenazine induced ptosis for lead compounds 7a and 9a. Optimal antitetrabenazine activity is associated with the 3 phenylspiro[isobenzofuran 1(3H),4' piperidine] moiety where nitrogen is basic. Modification of this moiety by introduction of large nitrogen substituents or a C-3 substituent > H significantly reduced antitetrabenazine activity. A series of analogue with aromatic substituents was investigated; however, few of these compounds were significantly more active than 7a and 9a. Compound 9a was selected for additional studies.
