A ligand having the structure or its enantiomer; (I) wherein: each one of R.sub.a, R.sub.b, R.sub.c and R.sub.d is selected from alkyl, cycloalkyl, and aryl; the bridge group is selected from CH.sub.2NH; *CH(CH.sub.3)NH(C*,R); and the organocatalyst is an organic molecule catalyst covalently bound to the bridge group. Also, a catalyst having the structure or its enantiomer: (II) wherein: each one of R.sub.a, R.sub.b, R.sub.c and R.sub.d is selected from alkyl, cycloalkyl, and aryl; the bridge group is selected from CH.sub.2NH; *CH(CH.sub.3)NH(C*,R); and *CH(CH.sub.3)NH(C*,S); the organocatalyst is an organic molecule catalyst covalently bound to the bridge group; and M is selected from the group consisting of Rh, Pd, Cu, Ru, Ir, Ag, Au, Zn, Ni, Co, and Fe. ##STR00001##

A method of making antidegradant compounds is disclosed, in which a p-phenylenediamine is reacted with an alpha-hydroxy carbonyl compound to thereby obtain an enediamine, which is reduced to thereby obtain a mixture comprising the antidegradant compound.

A method of making antidegradant compounds is disclosed, in which a p-phenylenediamine is reacted with an alpha-hydroxy carbonyl compound to thereby obtain an enediamine, which is reduced to thereby obtain a mixture comprising the antidegradant compound.

A method of making antidegradant compounds is disclosed, in which a p-phenylenediamine is reacted with an alpha-hydroxy carbonyl compound to thereby obtain an enediamine, which is reduced to thereby obtain a mixture comprising the antidegradant compound.

Methods of making antidegradant compounds are disclosed in which a p-phenylenediamine is reacted with a dicarbonyl to thereby obtain a diimine, which is reduced to obtain mixtures comprising the antidegradant compound.

Methods of making antidegradant compounds are disclosed in which a p-phenylenediamine is reacted with a dicarbonyl to thereby obtain a diimine, which is reduced to obtain mixtures comprising the antidegradant compound.

Methods of making antidegradant compounds are disclosed in which a p-phenylenediamine is reacted with a dicarbonyl to thereby obtain a diimine, which is reduced to obtain mixtures comprising the antidegradant compound.

Antidegradant compounds are disclosed, and methods of making them, that are represented by the formula I:

##STR00001## wherein each X is independently selected from the group consisting of ethyl, methyl, or hydrogen.

Also disclosed are diimine intermediates corresponding to formula III:

##STR00002## wherein each X is independently selected from the group consisting of ethyl, methyl, or hydrogen. These intermediates themselves exhibit antidegradant activity.

Antidegradant compounds are disclosed, and methods of making them, that are represented by the formula I:

##STR00001## wherein each X is independently selected from the group consisting of ethyl, methyl, or hydrogen.

Also disclosed are diimine intermediates corresponding to formula III:

##STR00002## wherein each X is independently selected from the group consisting of ethyl, methyl, or hydrogen. These intermediates themselves exhibit antidegradant activity.

Antidegradant compounds are disclosed, and methods of making them, that are represented by the formula I:

##STR00001## wherein each X is independently selected from the group consisting of ethyl, methyl, or hydrogen.

Also disclosed are diimine intermediates corresponding to formula III:

##STR00002## wherein each X is independently selected from the group consisting of ethyl, methyl, or hydrogen. These intermediates themselves exhibit antidegradant activity.