1069130-92-2Relevant academic research and scientific papers
Gold(I)-catalyzed hydroamination as a general approach toward the synthesis of substituted hydroisoquinolines: Remarkable acceleration by ethanol
Enomoto, Taro,Obika, Shingo,Yasui, Yoshizumi,Takemoto, Yoshiji
, p. 1647 - 1650 (2008)
Construction of 1,2-dihydroisoquinolines and l-alkylidenyl-l,2,3,4- tetrahydroisoquinolines through cationic gold(I) complex catalyzed hydroamination of the corresponding alkynyl carbamates has been demonstrated. In the presence of EtOH, the reaction proceeded smoothly at room temperature with low catalyst loading (1-3 mol%). Thieme Stuttgart.
Gold(I)-catalyzed tandem reactions initiated by hydroamination of alkynyl carbamates: Application to the synthesis of nitidine
Enomoto, Taro,Girard, Anne-Lise,Yasui, Yoshizumi,Takemoto, Yoshiji
supporting information; experimental part, p. 9158 - 9164 (2010/03/02)
(Chemical Equation Presented) As a convenient and direct synthesis of 1,2-dihydroisoquinolines, the gold(I)-catalyzed intramolecular hydroamination of (2-alkynyl)benzyl carbamates has been developed. The reaction with cationic gold(I) complex [AuCl(PPh3)/AgNTf2] proceeded at room temperature, giving the desired 6-endo adducts. The addition of alcohol efficiently promoted the reaction, and the amount of the catalyst could be reduced to 1 mol %. However, the alkynes bearing either an electron-deficient aryl group or an alkyl group resulted in predominant production of 5-exo adducts. In such cases, use of a bulky gold catalyst, AuCl[(o-biPh)( tBu)2P]Cl/AgNTf2, improved the regioselectivity, giving the 6-endo adducts in better yields. Furthermore, the hydroamination of alkynyl carbamates bearing an acetal or enone was successfully applied to the concise synthesis of tetracyclic heterocycles such as nitidine via the single catalyst-mediated tandem cyclization which consists of a condensation or a Michael addition of the resulting enecarbamates.
