Reactivity and diastereoselectivity of Grignard reagents toward the hydrazone functionality in toluene solvent
摘要:
Grignard reagents, in toluene solvent, display a strongly increased reactivity toward the hydrazone functionality. With the chiral synthon 1, a highly diastereoselective addition occurs, through chelation control, whereas with pyrazolines 4 and 9 only the d,l diastereomer is formed, leading to a very short synthesis of 1,3-diphenyl-1,3-diaminopropane (11).