New chiral bidentate ligands containing thiazolyl and pyridyl donors for copper-catalyzed asymmetric allylic oxidation of cyclohexene

Three Properties in One Coordination Complex: Chirality, Spin Crossover, and Dielectric Switching

“…All chemicals were commercially available and were used as received. Potassium bis(1‐pyrazolyl)borohydride (Kbpz), ( R )‐4,5‐pinenepyridyl‐2‐pyrazine [( R )‐L 1 ], and ( S )‐4,5‐pinenepyridyl‐2‐pyrazine [( S )‐L 1 ] were prepared according to published procedures …”

Transition metal-catalyzed C–H activation reactions: diastereoselectivity and enantioselectivity

“…207,208 In particular, the carene-derived bipyridine ligand 441 afforded the allylic oxidation product of cycloheptene in 82% ee, albeit in low yield (35%) in 96 h (Table 22). 209 Other variations of chiral pyridine [210][211][212] and 1,10-phenanthroline (442) 213,214 ligands, however, provided low levels of enantioselectivity. While the asymmetric variant of the Cu-catalyzed Kharasch-Sosnovsky reaction has evolved greatly over the course of last two decades, several limitations remain to be overcome.…”

Metal-catalyzed asymmetric reactions enabled by organic peroxides

“…101 A new amido-oxazoline ligand was investigated in the asymmetric Kharasch–Sosnovsky reaction of cyclohexene with tert -butyl-4-nitrobenzoperoxoate by Samadi et al and the reaction afforded the ester in good yield (70%) and excellent enantioselectivity (96% ee) (Scheme 13, L39 ). 102 Two types of thiazoline ligands, L40 103 and L41 104 (Scheme 29), were synthesized by the Kwong and Fu groups, respectively. And, moderate yields and enantioselectivities were obtained in the allylic oxidation of cycloalkenes with these ligands.…”