N-Methyl- and N-benzyl-4-amino[2.2]paracyclophanes as unique planar chiral auxiliaries
Abstract
Efficient production of racemic and homochiral N-alkyl[2.2]paracyclophanes from [2.2]paracyclophane via racemic and homochiral 4-carboxy[2.2]paracyclophane is described, including an excellent procedure for the synthesis of homochiral 4-amino[2.2]paracyclophane. Enolisation followed by electrophilic attack proceeds with diastereoselectivities varying from excellent to modest and the chiral auxiliaries are readily recovered in good yields; the configurational stability of the α-haloamides produced is examined.