767-58-8Relevant articles and documents
Davis,Venuto
, p. 274 (1970)
Reductive Cyclization of o-(3-Butenyl)fluorobenzene at Mercury and Lead Cathodes
Loffredo, David M.,Swartz, James E.,Kariv-Miller, Essie
, p. 5953 - 5957 (1989)
The cathodic behavior of o-(3-butenyl)fluorobenzene (1) at mercury and lead cathodes in DMF was investigated.Cyclic voltammograms were recorded, and the products of preparative electrolyses were isolated and identified.The reduction products at either cathode were 1-methylindane (3) and 3-butenylbenzene (2), the first predominating in all experiments with dry solvent.The effects of various reaction conditions on the product composition were studied, and the highest yield of 3 was obtained at a lead cathode at 22 deg C (3/2 = 3.8).Dimethylpyrrolidinium (DMP+) was tested as a possible catalyst for the reduction of 1.It catalyzed the reaction and increased the proportionate amount of the cyclic product.However the mediated process at lead was very inefficient.The mechanism for the reductive cyclization of 1 at mercury and lead and the mediation by DMP+ are discussed.It is proposed that tetraalkylammonium-metals are involved in these processes.
Computational Insight into 1,2-Diamine, -Diether, and -Amino Ether Chiral Ligand-Mediated Carbolithiation: A Case of Enantioinduction Reversal
Guyon, Hélène,Castanet, Anne-Sophie,Boussonnière, Anne
, p. 8933 - 8943 (2020/08/28)
trans-1,2-Cyclohexanediamine, -diether, and -amino ether were compared as chiral inducers in the asymmetric intramolecular carbolithiation of olefinic aryllithiums. Switching from diamine to ethereal ligands inverts the sense of asymmetric induction. This reversal of stereoselectivity was investigated through density functional theory calculations. High enantioselectivities observed with diether and amino ether ligands arise from favorable weak interactions between the ligand and the substrate. The relative efficiency of the three ligands and sense of stereoinduction for the most efficient diether and amino ether ligands prove to be foreseeable by modeling the reaction with the parent achiral 1,2-bidentate additives and comparing the diastereomeric transition states stemming from the two half-chair conformations of their lithium chelate.
Exploiting the radical reactivity of diazaphosphinanes in hydrodehalogenations and cascade cyclizations
Cheng, Jin-Pei,Yang, Jin-Dong,Zhang, Jingjing
, p. 4786 - 4790 (2020/06/18)
The remarkable reducibility of diazaphosphinanes has been extensively applied in various hydrogenations, based on and yet limited by their well-known hydridic reactivity. Here we exploited their unprecedented radical reactivity to implement hydrodehalogenations and cascade cyclizations originally inaccessible by hydride transfer. These reactions feature a broad substrate scope, high efficiency and simplicity of manipulation. Mechanistic studies suggested a radical chain process in which a phosphinyl radical is generated in a catalytic cycle via hydrogen-atom transfer from diazaphosphinanes. The radical reactivity of diazaphosphinanes disclosed here differs from their well-established hydridic reactivity, and hence, opens a new avenue for diazaphosphinane applications in organic syntheses.
Remote, Diastereoselective Cobalt-Catalyzed Alkene Isomerization-Hydroboration: Access to Stereodefined 1,3-Difunctionalized Indanes
Léonard, Nadia G.,Palmer, W. Neil,Friedfeld, Max R.,Bezdek, Máté J.,Chirik, Paul J.
, p. 9034 - 9044 (2019/10/02)
The remote, diastereoselective hydroboration of 2- and 3-substituted indenes with a 2,2′:6′,2″-terpyridine cobalt alkyl precatalyst is described that maintains high regio- and stereoselectivity independent of the starting position of the alkene. Several 1,2- and 1,3-disubstituted indanyl boronate esters were obtained with exclusive (>20:1 dr) selectivity for the trans diastereomer including synthetically versatile, stereodefined diboron derivatives. Alkene isomerization by a putative cobalt hydride intermediate precedes carbon-boron bond formation, leading to the observed regioselectivity for boron incorporation at the unsubstituted C(sp3)-H benzylic site. The regio- and diastereoselectivity of the transformation were maintained independent of the starting position of the alkene, as demonstrated by hydroboration of three isomers of methyl-substituted indene. Deuterium-labeling experiments support rapid and reversible insertion and β-hydride elimination to isomerize 3-methylindene and 1-exo-methylene-indane, accounting for the isotopic distribution observed in the products. Mechanistic studies, including stoichiometric experiments, density functional theory calculations, and kinetic analysis, support a mechanism in which 2,3-alkene insertion into a cobalt hydride intermediate determines both the regio- and diastereoselectivity of the catalytic reaction. Synthetic applications of the indanyl boronate esters were demonstrated through the elaboration of the products to several examples of 1,3-disubstituted indanes, important carbocyclic structural motifs in both pharmacological and bioactive molecules.
