41852-27-1Relevant articles and documents
Visible-light photoredox catalysis in flow
Tucker, Joseph W.,Zhang, Yuan,Jamison, Timothy F.,Stephenson, Corey R. J.
, p. 4144 - 4147 (2012)
Photoredox catalysis: A variety of organic transformations mediated by visible-light-active photoredox catalysts have been conducted in a photochemical flow reactor. The reactor design is very simple and can be easily implemented in any laboratory (see pi
Isothiourea-Catalyzed Enantioselective Addition of 4-Nitrophenyl Esters to Iminium Ions
Arokianathar, Jude N.,Frost, Aileen B.,Slawin, Alexandra M. Z.,Stead, Darren,Smith, Andrew D.
, p. 1153 - 1160 (2018/02/14)
Isothioureas catalyze the enantioselective addition of 4-nitrophenyl esters to tetrahydroisoquinoline-derived iminium ions. 4-Nitrophenoxide, generated in situ from initial N-acylation of the isothiourea by the 4-nitrophenyl ester, is used to facilitate catalyst turnover in this reaction process. Optimization showed that 4-nitrophenyl esters give the best reactivity in this protocol over a range of alternative aryl esters, with the observed enantioselectivity markedly dependent on the nature of the iminium counterion. Highest yields and enantioselectivity were obtained using iminium bromide ions generated in situ via photoredox catalysis using BrCCl3 and Ru(bpy)3Cl2 (0.5 mol %) and commercially available tetramisole (5 mol %) as the Lewis base catalyst. The scope and limitations of this procedure was developed, giving the desired β-amino amide products in up to 96% yield, 79:21 diastereomeric ratio (dr), and ermajor (2R,1′S) 99.5:0.5.
A metal-free cyclic iminium induced one-pot double annulation cascade: Access to dihydroisoquinolinium (DHIQ) salts
Sagar,Nagarjuna Babu, Venkata,Shinde, Anand H.,Sharada, Duddu S.
, p. 10366 - 10370 (2016/11/18)
A reactive cyclic iminium induced one-pot Groebke-Blackburn-Bienayme (GBB) double annulation cascade (DAC) for the synthesis of skeletally diverse DHIQ salts has been described. The key features of this protocol are transition-metal and solvent-free, mild reaction conditions, robust method, one-step construction of two privileged heterocyclic rings, clean reaction profile and operational simplicity.