18636-52-7Relevant academic research and scientific papers
The SRN1 Photoarylation of Indenyl Anions
Tolbert, Laren M.,Siddiqui, Shahabuddin
, p. 1744 - 1751 (1984)
Irradiation of Me2SO solutions of indenyl anion and its phenylated analogues in the presence of bromobenzene produces the higher phenylated indenes.Thus indenyl anion (1b) yields 3-phenylindene (3a), 1-phenylindenyl anion (3b) yields 1,3- and 1,1-diphenylindene, 2-phenylindenyl anion (2b) produces 2,3-diphenylindene, 1,3-diphenylindenyl anion (6b) produces 1,1,3- and 1,2,3-triphenylindene, and 1,2-diphenylindenyl anion (5b) produces 1,2,3-triphenylindene (8).In liquid ammonia and tetrahydrofuran more complex reaction pathways are observed.The regiochemistry of phenylation is attributed to radical attack at the most basic site, in accord with a previously published model.
Intramolecular addition of triarylmethanes to alkynes promoted by KOtBu/DMF: A synthetic approach to indene derivatives
Chen, Yan-Yan,Chen, Zhen-Yu,Zhang, Niu-Niu,Chen, Jia-Hua,Zhang, Xue-Jing,Yan, Ming
, p. 599 - 606 (2016/02/19)
A method for the intramolecular addition of triarylmethanes to alkynes has been developed. The reaction was efficiently promoted by KOtBu/DMF without any transition-metal catalyst. A variety of indene derivatives were prepared in moderate to good yields. A cascade cyclization of 2-alkyl-substituted substrates at elevated reaction temperature gave bicyclic indene derivatives. The reaction is proposed to proceed through the generation of a triphenylmethyl radical. Indene derivatives were prepared by the intramolecular addition of triarylmethanes to alkynes promoted by KOtBu/DMF. A cascade cyclization of 2-alkyl-substituted substrates at elevated reaction temperature gave bicyclic indene derivatives. A free-radical reaction mechanism is proposed.
Sigmatropic Rearrangements of 1,1-Diarylindenes. Migratory Aptitudes of Aryl Migration in the Ground and Electronically Excited States
Manning, Carl,McClory, Michael R.,McCullough, John J.
, p. 919 - 930 (2007/10/02)
The photochemical and thermal rearrangements of 1,1-diarylindenes to give 2,3-diarylindenes have been investigated.Migratory aptitudes of p-X-phenyl vs. phenyl were determined for X =Br,CN, and OCH3 in the photochemical and thermal migrations.The identities of the products of these rearrangements were established by unambiguous synthesis, and the synthetic work is described.Product ratios were generally determined by NMR techniques, but VPC and isotope dilution were also used in the case of 1-(p-cyanophenyl)-1-phenylindene reactions.The excited-state reactions (direct and triplet sensitized) are highly selective, migration of the substituted phenyl group being favored for all three substituents.The thermal reactions, in contrast, are quite unselective, phenyl migrating almost as readily as the substituted phenyl group in all cases.Quantum yields for the rearrangement in the case of 1,1-diphenylindene and 1-(p-cyanophenyl)-1-phenylindene were 0.80 and 0.4, respectively (direct irradiation), and 0.43 and 0.53 (sensitized reactions).The results of the thermal reactions and results from the literature are discussed in terms of bond-dissociation energies and transition-state-delocalization energies calculated by using the Hueckel theory.Neither approach led to a satisfactory interpretation.The excited-state migrations are consistent with charge-transfer stabilization of the transition state, which can be estimated from oxidation and reduction potentials by using Weller's equation.
