Asymmetric induction in the creation of tri- and tetra-substituted carbon stereocentres by the intramolecular heck reaction

Chiral Phosphoric Acid Catalyzed Asymmetric Friedel–Crafts Alkylation of Indole with 3‐Hydroxyisoindolin‐1‐one: Enantio­selective Synthesis of 3‐Indolyl‐Substituted Isoindolin‐1‐ones

“…These methods involve an intramolecular Heck reaction of chiral N-vinyl o-iodobenzamide, [4] a tandem nucleophilic 1,2-addition/ring-closure procedure from SAMP or RAMP [(S)-or (R)-1-amino-2-methoxymethylpyrrolidine] hydrazones, [5] radical cyclization of allenamide containing a chiral auxiliary, [6] anionic cyclization and re-aromatization of N-benzylbenzamide derivatives in the presence of a chiral base, [7] nucleophilic addition or hydride reduction of chiral acyliminium ion, [8] as well as chiral auxiliary mediated carbocation methods. [9] The main drawback of these protocols is that [ …”

Catalytic Asymmetric Synthesis of Isoindolinones

“…Chiral isoindolinones have attracted considerable attention from organic synthetic chemists and great progress has been made to obtain such lactam compounds. Traditional methodologies need a chiral auxiliary, which may be tedious to cleave. These works will not be introduced in detail in this review.…”

“…[6] Chiral isoindolinones have attractedc onsiderable attention from organic synthetic chemists and great progress has been made to obtain such lactam compounds. Traditionalmethodologies [7][8][9][10][11][12] need ac hiral auxiliary,w hich may be tedious to cleave. These works will not be introduced in detail in this review.B eginning around 2010, particulare mphasis has been put on transition-metal catalyzed and organocatalyzed asymmetrics ynthesis of such phthalimidines.…”

Desymmetrisation of a diallyl system by intramolecular Heck reaction

“…The initial attempts followed a literature precedent [6] showing high efficient cyclisation to form a five-membered ring with palladium (II) salts in acetonitrile, but under these conditions no product was observed. Variations of base, palladium source and temperature proved ineffective in acetonitrile solvent, with some product being observed with the less hindered base diethylamine replacing triethylamine, and the use of PdCl 2 (PPh 3 ) 2 rather than Pd 2 (dba) 3 , but a satisfactory yield was never obtained.…”

“…Upon moving to the less polar solvent DMF, efficient cyclisation was observed with this base/palladium source combination even at room temperature, and by extending the reaction time an optimum combination was found to be DMF solvent with diethylamine as base, with palladium dichloride bis(triphenylphosphine) as the catalyst source with a reaction time of 5 h. Under these conditions the Heck reaction proceeded to give an 86% yield of 1-allyl-3-methylene-indan-1-ol 4 with no significant by-products. Although DMF is the more common solvent for the Heck reaction it is surprising that such a difference is noted between the solvents, especially given the precedent [6] for the efficiency of acetonitrile in cyclisation to a five-membered ring in another system. In the cases (entries [1][2][3][4] where no yield is given for product the starting material is recovered essentially unchanged, and thus it appears to be the initial oxidative insertion into the aryl iodide which is retarded in these cases rather than the cyclisation itself, hence it is difficult to see why variations in the reactivity of substrate alkenes could cause the apparent differences.…”