BINOL‐Fused Maleimides – A New Class of C₂‐Symmetric Chiral Imides

Abstract

The first synthesis of BINOL‐fused maleimides has been developed. This new chiral scaffold is easily accessible from various BINOL analogues and 2,3‐dihalomaleimide derivatives under basic conditions. It can be easily functionalized on the BINOL moiety and is an entry towards promising new classes of chiral organocatalysts and ligands.

Copper‐Catalyzed Regioselective Cross‐Dehydrogenative Coupling of Coumarins with Benzylic Csp3–H Bonds

“…In a preliminary work, aiming at developing a new family of chiral N ‐hydroxymaleimide organocatalysts, we described the facile synthesis of key intermediate 1 (Figure 1). 10 This molecule is somewhat unusual in that it has C 2 symmetry and so possesses two iodine atoms within the same chiral environment. To the best of our knowledge, no 3,3′‐diiodo‐BINOL derivative has been reported in the context of hypervalent iodine chemistry.…”

Asymmetric Addition of Triethylaluminium to Aromatic Aldehydes Catalyzed by Titanium‐(5,5’‐Biquinoline‐6,6’‐Diol) Complexes

“…of Et 3 Al was used, the corresponding alcohol was obtained in 100% conversion with 86.6% ee (entry 9). The catalytic amount of the ligand was also screened (entries [12][13][14][15][16]. When the reaction was carried out without the ligand, low conversion was observed (entry 12).…”

“…) are one of the widely used chiral auxiliaries in stoichiometric and catalytic asymmetric synthesis . Thus, numerous synthetic approaches have been developed for the synthesis of optically active BINOL‐type ligands . However, the C 2 ‐symmetric ligands containing a heterocyclic moiety have drawn far less attention.…”

“…1,2 Thus, numerous synthetic approaches have been developed for the synthesis of optically active BINOLtype ligands. [3][4][5][6][7][8][9][10][11][12][13] However, the C 2 -symmetric ligands containing a heterocyclic moiety have drawn far less attention. Only a few pyridyl-containing ligands were reported to give good enantioselectivities with a high level of catalyst usage in Ru-catalyzed asymmetric hydrogenation [14][15][16] and asymmetric addition of diethylzinc to aldehydes.…”

The Hairpin Furans: Easily Prepared Hybrids of Helicenes and Twisted Acenes

“…For unknown reasons, the multistep synthesis3 of this molecule is erratic in our hands, and we have found it preferable to prepare compound 1 by a simple chromic acid oxidation of 2,2 ′ ‐dimethoxy‐1,1 ′ ‐binaphthalene. The yield of 1 in this process is poor (4 %), but its isolation is simple, and the starting material is readily available9 (see the Supporting Information).…”