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The synthesis and unique reactivity of a series of arylsulfonate-based nucleophile assisting leaving groups (NALG) containing oligomeric ether units attached to the arylsulfonyl in the ortho orientation are described. The reactions of a variety of these ether-containing alkyl sulfonates with metal halides proceeded at substantially greater rates ether-electronically similar sulfonates.

A study of the role of base in the isomerization of manganese-coordinated conjugated alkynyl carbonyls to the corresponding allenyl carbonyls is described. A series of amine bases is also examined for their efficacy in the isomerization revealing a strong dependence on pK(sub a).

A series of arylsulfonate nucleophile assisting leaving groups (NALGs) are prepared in which the metal chelating unit is attached to the aryl ring via an ether linker. The NALGs have displayed significant rate enhancements in halogenation reactions using metal halides and the studies have shown that rate enhancements of these nucleophilic halogenation reactions are facilitated by stabilization of charge in the transitions state rather than through strong precomplexation with metal cation.

The stereospecificity and utility of the sulfonate/TiCl4 technique in the synthesis of a variety of alkyl chlorides are demonstrated. This technique offers an important alternative to existing methods for the synthesis of secondary alkyl chlorides with retention of configuration.

The molecular recognition properties of the nucleobases instruct the formation of complex three-dimensional architectures in natural and synthetic systems; relatively unexplored is their use as building blocks for π-conjugated materials where they might mutually tune electronic and supramolecular structures. Toward this goal, an introductory set (1a-d and 2a-d) of six purine-terminated and two pyrimidine-terminated π-conjugated oligomers has been synthesized and used to develop experimental electronic and photophysical structure-property trends. Unlike 2,2':5',2"-terthiophene (TTT) derivatives 2a-d, intramolecular charge transfer dominates oligomers 1a-d bearing a 4,7-bisthienylbenzothiadiazole (TBT) spacer due to the strong electron-accepting ability of its benzothiadiazole (BTD) ring. The resulting donor-acceptor-donor systems feature lower HOMO-LUMO gaps than the terthiophene-linked nucleobases (ΔEg ~ 1.8 eV vs 2.4 eV based on electrochemical measurements), and the lowest so far for π-conjugated molecules that include nucleobases within the π-framework. Experiments reveal a dependence of photophysical and electronic structure on the nature of the nucleobase and are in good agreement with theoretical calculations performed at the B3LYP/6-31+G** level. Overall, the results show how nucleobase heterocycles can be installed within π-systems to tune optical and electronic properties. Future work will evaluate the consequences of these information-rich components on supramolecular π-conjugated structure. [ABSTRACT FROM AUTHOR]