41303-44-0Relevant academic research and scientific papers
Ligand-Controlled Regiodivergence in Nickel-Catalyzed Hydroarylation and Hydroalkenylation of Alkenyl Carboxylic Acids**
Deng, Ruohan,Engle, Keary M.,Fu, Yue,Gao, Yang,Li, Zi-Qi,Liu, Peng,Tran, Van T.
supporting information, p. 23306 - 23312 (2020/10/19)
A nickel-catalyzed regiodivergent hydroarylation and hydroalkenylation of unactivated alkenyl carboxylic acids is reported, whereby the ligand environment around the metal center dictates the regiochemical outcome. Markovnikov hydrofunctionalization products are obtained under mild ligand-free conditions, with up to 99 % yield and >20:1 selectivity. Alternatively, anti-Markovnikov products can be accessed with a novel 4,4-disubstituted Pyrox ligand in excellent yield and >20:1 selectivity. Both electronic and steric effects on the ligand contribute to the high yield and selectivity. Mechanistic studies suggest a change in the turnover-limiting and selectivity-determining step induced by the optimal ligand. DFT calculations reveal that in the anti-Markovnikov pathway, repulsion between the ligand and the alkyl group is minimized (by virtue of it being 1° versus 2°) in the rate- and regioselectivity-determining transmetalation transition state.
Expeditious approach to pyrrolophenanthridones, phenanthridines, and benzo[ c ]phenanthridines via organocatalytic direct biaryl-coupling promoted by potassium tert -butoxide
De, Subhadip,Mishra, Sourabh,Kakde, Badrinath N.,Dey, Dhananjay,Bisai, Alakesh
, p. 7823 - 7844 (2013/09/12)
A methodology involving a "transition metal-free" intramolecular biaryl-coupling of o-halo-N-arylbenzylamines has been developed in the presence of potassium tert-butoxide and an organic molecule as catalyst. The reaction appears to proceed through KOtBu-promoted intramolecular homolytic aromatic substitution (HAS). Interestingly, this biaryl coupling also works in the presence of potassium tert-butoxide as sole promoter. On extending our approach further, we found that N-acyl 2-bromo-N-arylbenzylamines undergo a one-pot N-deprotection/biaryl coupling followed by oxidation, thus offering an expeditious route to the phenanthridine and benzo[c]phenanthridine skeletons. The strategy has been applied to a concise synthesis of Amaryllidaceae alkaloids viz. oxoassoanine (1b), anhydrolycorinone (1d), 5,6-dihydrobicolorine (2d), trispheridine (2b), and benzo[c]phenanthridines alkaloids dihydronitidine (3b), dihydrochelerythidine (3d), dihydroavicine (3f), nornitidine (3h), and norchelerythrine (3j).
Synthesis of 1-tetralone derivatives using a Stille cross coupling/friedel crafts acylation sequence
Vercouillie, Johnny,Abarbri, Mohamed,Parrain, Jean-Luc,Duchene, Alain,Thibonnet, Jerome
, p. 3751 - 3762 (2007/10/03)
An efficient method of synthesis of 1-tetralones has been achieved featuring a Stille cross-coupling reaction as the key step.
A convenient procedure for the synthesis of 1-tetralone dertivatives using a Suzuki coupling-Friedel-Crafts acylation sequence
Esteban, Gemma,Lopez-Sanchez, Miguel A.,Martinez, Ma. Eugenia,Plumet, Joaquin
, p. 197 - 212 (2007/10/03)
The reported 1-tetralone derivatives have been synthesized from arylbromides using as keys steps a Suzuki coupling followed by intramolecular Friedel-Crafts acylation.
Total synthesis of homoerythrinan alkaloids, schelhammericine and 3-epischelhammericine
Tsuda, Yoshisuke,Ohshima, Takeshi,Hosoi, Shinzo,Kaneuchi, Satomi,Kiuchi, Fumiyuki,Toda, Jun,Sano, Takehiro
, p. 500 - 508 (2007/10/03)
Total syntheses of two homoerythrinan alkaloids, schelhammericine and 3-epischelhammericine, are described. Photocycloaddition of a dioxopyrrolobenzazepine to 1-methoxy-3-trimethylsilyloxybutadiene afforded, in a regio- and stereo-specific manner, the cyc
Total synthesis of the homoerythrinan alkaloids, schelhammericine and 3-epischelhammericine
Tsuda,Hosoi,Ohshima,et al.
, p. 3574 - 3577 (2007/10/02)
This stereo-coantrolled total synthesis of the title alkaloids, both in racemic form, is the first synthesis of the naturally occurring homoerythrinan alkaloids.
Direct Synthesis of Benzophenanthridines and Benzophenanthridones via SRN1 Reactions
Beugelmans, Rene,Chastanet, Jacqueline,Ginsburg, Helene,Quintero-Cortes, Leticia,Roussi, Georges
, p. 4933 - 4938 (2007/10/02)
A straightforward and high-yield route to the 11,12-dihydrobenzophenanthridine (3) and 11,12-dihydrobenzophenanthridone (14) ring systems is based upon an SRN1 reaction between 2-halobenzylamines 1 or 2-halobenzoic acids 11 and enolates derived from tetralones 2.The efficient dehydrogenation of 3 or 14 gives the benzophenthridines 4 or benzophenanthridones 15.Use of properly substituted reactants leads to nitidine, avicine, and fagaronine and to analogues of those natural products.
SYNTHESIS OF SANGUINARINE, CHELERYTHRINE, AND OXYSANGUINARINE
Smidrkal, Jan
, p. 1412 - 1420 (2007/10/02)
Benzophenanthridines Va and Vb have been prepared by photocyclization of amines IVa and IVb and transformed into the alkaloids sanguinarine (VIa) and chelerythrine (VIb).Oxysanguinarine (XIV) has been prepared from diazoketone XVIII.
