Physical Sciences and Mathematics Commons^™

Synthesis And Metalation Of Internally Alkylated Porphyrinoids, Alissa Nicole Latham

Theses and Dissertations

The mechanism behind alkyl migration in palladium(II) benzocarbaporphyrins was investigated through the synthesis of a 23-methylcarbaporphyrin. It was found that palladium insertion led to methyl group migration to C21 and it is proposed that this occurs through an oxidative addition onto the palladium metal center, followed by a reductive elimination to transfer the methyl to the internal carbon. A similar rearrangement was observed when 23-methylcarbaporphyrin was reacted with [Rh(CO)2Cl]2 and resulted in the formation of a rhodium(III) complex containing a three-membered rhodacycle. The syntheses of rhodium(I) and rhodium(III) derivatives of other carbaporphyrins, including 21- and 22-methylbenzo-carbaporphyrins, were probed and four …

Initial Studies On A Novel Target-Promoted Dna Alkylation System, Ting Xu

Theses and Dissertations

A novel target-promoted DNA alkylation system was designed, which consists of a DNA intercalating/alkylating quinone methide (QM) precursor, a removable amine linker, and a sequence-specific delivery. The QM in this system was regenerated by eliminating the amino linker promoted by the hydrophobic interaction between the target DNA and the intercalating QM precursor. Three alkylation model systems (methoxyl polycyclic system, intramolecular hydrogen bonding system and biaryl system) were proposed and synthesized. The potential DNA QM alkylation was investigated by deoxyadenosine (dA) and deoxyguanosine (dG) alkylation with the biaryl system. Only one deoxynucleoside adduct was observed when dA or dG reacted with …

N9 Alkylation And Glycosylation Of Purines; A Practical Synthesis Of 2-Chloro-2'-Deoxyadenosine, Minghong Zhong

Theses and Dissertations

(a) The Robins reagent [2-acetamido-6-O-(diphenylcarbamoyl)purine] was utilized for glycosylation under Lewis acid conditions. Regioselectivity of glycosylation depends on the glycosyl donor and its 2-O- or 2-N-protecting group. Regioselective N9 glycosylation of 2-acetamido-6-O-(diphenylcarbamoyl)purine with problematic glucosamine has been accomplished by protecting the amino function as a phthalimido group with consequent stabilization of the oxocarbenium cation, and lowering the activation energy by introduction of trichloroacetimidate at the anomeric carbon.

(b) 6-Heteroaryl functions [6-(1,2,4-triazol-4-yl) and 6-(imidazol-1-yl)] were introduced into purine derivatives for regioselective N9 alkylation. The regiospecificity of alkylation mainly results from steric effects due to the coplanar conformation of the two linked …