Abstract
An iron-catalyzed asymmetric oxidative homo-coupling of 2-naphthols for the synthesis of 1,1′-Bi-2-naphthol (BINOL) derivatives is reported. The coupling reaction provides enantioenriched BINOLs in good yields (up to 99%) and moderate enantioselectivities (up to 81:19 er) using an iron-complex generated in situ from Fe(ClO4)2 and a bisquinolyldiamine ligand [(1R,2R)-N1,N2-di(quinolin-8-yl)cyclohexane-1,2-diamine, L1]. A number of ligands (L2–L8) and the analogs of L1, with various substituents and chiral backbones, were synthesized and examined in the oxidative coupling reactions.
Highlights
Chiral compounds have aroused much attention from organic chemists due to their prevalence in natural products, bioactive molecules, functional materials, and their wide applications in asymmetric transformations [1]
Many elegant methods have been established for the asymmetric synthesis of axially chiral compounds, both employing transition-metal catalysts [2]
Discussion and it was interesting to find that the catalysts used were generated by in situ mixing of an ironSynthesis salt and ofanBisquinolyldiamine aminopyridine ligand
Summary
Chiral compounds (atropisomers) have aroused much attention from organic chemists due to their prevalence in natural products, bioactive molecules, functional materials, and their wide applications in asymmetric transformations [1]. BINOL-derived ligands/catalysts (i.e., BINAP [11], BINAM [12], chiral phosphoric acid [13], chiral phosphoramidite [14], and BINSA [15]; Figure 1) have been designed and synthesized. The emergence of such a library of ligands/catalysts has brought marvelous contributions to the synthetic community, with tremendously efficient asymmetric transformations such as reductive coupling [16], allylation [17], ene-type [18], and Aldol [19] reactions and axial chirality assembly [20]. Efficient vanadium-catalyzed [21] protocols were reported by the Uang [22], Chen [23], Gong [24,25,26], and Sasai [27,28,29] groups, independently
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
