Kenneth Allen Savin

Tachykinin receptor antagonists

The present invention relates to selective NK-1 receptor antagonists of Formula (I); or a pharmaceutically acceptable salt thereof, for the treatment of disorders associated with an excess of tachykinins

A study of the synthesis of triazoles using microwave irradiation

Herein we describe the conversion of a known [3+2] cycloaddition reaction between an azide and an acetylene from a thermally promoted reaction to a microwave assisted process. Modification of conditions including concentration, temperature, solvent type and time were investigated. This methodology study led us to use high concentration and high temperatures to achieve the desired fast reaction times and high yields.

Oxidations and Reductions

Reductions and oxidations are chemical transformations where electrons have been added or removed from a molecule. In organic chemistry, oxidation or reduction may not actually involve electron transfer, but rather may involve a change in oxidation number that is associated with the number of bonds an atom has to less electronegative atom like a hydrogen or to an atom that is more electronegative. The oxidation number or “oxidation state” of the molecule is relative and is indicative of the type of chemistry that carbon atom, and thus that molecule, is susceptible to. There have been many methods developed to effect the change of oxidation number or that change the oxidation state as a result of some other desired structural change. Although not usually considered significant in the same way that a carbon–carbon bond forming transformation may be, oxidations and reductions constitute a powerful tool in organic chemistry and provide us with a great opportunity to better understand the driving forces that make it possible to prepare the compounds that are such an important part of our everyday lives.

Introduction—Molecular Structure and Reactivity

To understand the way atoms bond to one another and then transform into new structures it is important to have a common set of rules and definitions. Herein, we describe key aspects of bonding, equilibrium, and driving forces that influence the structure and allow us to model and predict what are otherwise very complicated events. Many of the concepts presented in this chapter are a review for the student who has already taken the basic Organic series and the General Chemistry sequence, with a few new concepts and further explanations on some specific topics. This chapter helps create a common language and concepts that will be encountered in the book.

General Principles for Writing Reaction Mechanisms

The flow of electrons is fundamental to understanding the mechanism of a chemical transformation. The driving forces and key levers associated with the model we present are described in this chapter. These levers include electron flow and acid/base theory as it pertains to the flow of electrons, solvent effects and polarity, stability, and balancing reaction equations in organic chemistry.

Reactions Involving Acids and Other Electrophiles

Electrophiles are electron-deficient species that are attracted to an electron-rich center. Electrophiles react by accepting an electron pair in order to form a bond to a nucleophile including the interactions of a proton and a base. Electrophiles are often positively charged as a result of possessing an atom with a positive charge or an atom that does not have an octet of electrons. The formation, stability, and fate of carbocations are described in this chapter. The addition of nucleophiles to electrophiles as well as rearrangements, hydrolysis, and substitution processes that are affected by the interaction of an electrophilic species or facilitated by a Lewis acid will be described.

Radicals and Radical Anions

Abstract Radicals are species that contain one or more unpaired electrons. Although radical species are electron deficient, they are usually uncharged and this imparts properties and chemistries that are significantly different from that seen with cations or carbenes. Early radical chemistry was associated with high-energy and often uncontrolled/unpredictable processes, but over the years radical chemistry has matured into a well-developed set of tools that are both versatile and predictable and represent a significant contribution to our overall understanding of chemical processes. Key aspects of the mechanisms and outcomes of a variety of radical processes are described with an emphasis on understanding the forces that drive these reactions and their outcomes.

Reactions of Nucleophiles and Bases

A nucleophile is an electron donor (has an electron pair available for bonding) that bonds to an atom other than hydrogen. A base is an electron donor that bonds to hydrogen. The transformations that result from the action of bases or nucleophiles are numerous and varied. These transformations follow a set of principles and can be categorized leading to a level of understanding that can be applied across many situations. The types of electrophiles, as well as the type of nucleophiles, can have an effect on the transformation. Examples of a few types of processes are described and the rearrangements and outcomes of the action of nucleophiles and base-promoted transformations are presented.

Chapter 6 – Pericyclic Reactions

An organic reaction in which a cyclic transition state leads to a concerted transformation. A majority of these reactions are rearrangements and are consistent to the point of being very predictable using systems that have been developed upon numerous observations and hypotheses associated with molecular orbital theory. These transformations are commonly used because of their predictability and consistent performance. The reaction types are presented and the hypotheses and key influencing factors are described as general theories, systems of prediction, and supporting examples for the key transformations.