Source: Dissertation Abstracts International, Volume: 71-07, Section: B, page: 4261.

Adviser: John F. Hartwig.

Studies were conducted to develop conditions for the formation of enantiomerically enriched, alpha-branched, primary allylic amines from (E)-linear allylic carbonates in the presence of iridium catalysts, and to investigate the mechanism of iridium-catalyzed allylic substitution. In the course of these investigations, new methods were developed for the mono- and diallylation of ammonia, the allylation of two ammonia surrogates, the one-pot heterodiallylation of ammonia, and the one-pot allylation and acylation of ammonia. Mechanistic studies showed how the rate constants for individual steps of the catalytic cycle were affected by variations in nucleophile, leaving group, and substitution on the allyl.

The allylation of ammonia and ammonia surrogates was studied. Iridium-catalyzed allylation of ammonia with methyl cinnamyl carbonate occurs with high enantioselectivity to form a symmetric diallylamine. Protected, branched, primary allylic amines were synthesized from two ammonia surrogates, the alkali metal salts of trifluoroacetatnide and di-tert-butylitninodicarboxylate. Both ammonia surrogates react with a range of linear allylic methyl carbonates to form protected amines in high yield and excellent enantioselectivity in the presence of a catalyst generated from [Ir(COD)Cl]2 and a simplified phosphoramidite ligand that contains only one chiral center.

Selective monoallylation of ammonia with linear allylic ethyl carbonates occurs in the presence of an ethylene-bound metalacyclic iridium-phosphoramidite catalyst precursor and high concentrations of ammonia. The products were isolated in good yields and excellent enantiomeric excess. The crude products were also used without purification for the formation of heterodiallylamines and allylic amides in high yield and excellent enantiomeric excess.

Mechanistic studies were performed to determine the effects of different nucleophiles, leaving groups, and substituents on the allyl group on the rate of allylic substitution. The rates of reactions with different nucleophiles were affected by a proposed interaction with the alkyl carbonate leaving group that is formed during allylic substitution reaction. Reactions of allylic carbonates are slower with bulkier alkyl groups on the carbonate. Finally, differences in rates due to different substituents on the ally' group were caused by varying degrees of inhibition by the products of allylic substitution.