Reactivity of M-C bonds and catalytic formation of heterocycles Essay

Reactivity of M-C bonds and catalytic formation of heterocycles - Essay Example This branch deals with the synthesis, properties and application of heterocyclic compounds and their derivatives. Heterocyclics are largely categorized as unsaturated and saturated heterocyclics, depending on their structures(Pfaltz&Drury, 2004). The saturated heterocyclics have been noticed to behave like their acyclic derivatives. The core focuses of heterocyclic compound studies are the unsaturated derivatives of 5- and 6- membered rings, their applications and their predominance of low-numbered rings. Among the 5- and 6-membered unsaturated heterocyclics are pyridine, thiophene, pyrrole and furan. Similarly studied to a large extent are benzene-fused rings of these 5- and 6- membered unsaturated heterocyclics(Nakamura et al., 1998). These benzene-fused derivatives are quinoline, benzothiophene, indole, and  benzofuran for pyridine, thiophene, pyrrole, and furan respectively. The following are structures of a heterocyclic and a homocyclic compounds namely pyridine, a heterocycli c and cyclo-octasulfur, a homocyclic compound. From the structures of these compounds it is evident that the C-H bond is quite important in their reactions. In fact, it is the activation of this C-H bond that allows for the formation and introduction of other functionality groups/bonds such as M-C or C-C bonds to heterocyclic compounds(Benudhar et al., 2013). Pyridine Cyclo-octasulfur, The core theme in organometallic chemistry is the construction and transformation of metal-carbon bonds. Consequently, most of researches and literatures seem to focus on the traditional M-C bonds formed using the tetravalent carbon bond. However, fewer researchers have concentrated on non-traditional M-C bonds, often referred to as M-C cage bonds, which are found in carborane cages in which the carbon is hypervalent(Nakamura et al., 1998). This paper explores the reactivity of M-C bonds and outlines a plan for the catalytic formation of heterocyclics via the catalytic activation of the M-C bond. Spec ifically, the aim of this paper is the synthesis of some ligands that contain heterocycles or vinyl groups that can undergo C-H activation to form cyclometallated complexes(Benudhar et al., 2013). Further, the paper investigates the reactivity of the cyclometallated complexes with alkynes and alkenes. Thus, the goal is to assess the relative reactivity of different types of M-C bonds. One of the methods used in the catalytic synthesis of heterocycles is the amphibilic metal ligand activation (AMLA). In the AMLA process, the steps in the activation of the C-H bond entail the use of an electrophilic metal in combination with a deprotonation using an intramolecular base, frequently acetate. Chiral ligands are chemical compounds adapted for and largely used in the asymmetric synthesis of heterocyclic compounds. Chiral ligands are pure organic enantiomers that combine with metallic centers through the process of chelation to yield asymmetric catalysts(Nakamura et al., 1998). It is this c atalyst that later engages in the chemical reaction in which the chirality of a ligand is transferred to the product of the reaction. That is, while initially the ligand is chiral, at the end of the reaction, it is the product, which is chiral. In model situations or reactions, one equivalent catalyst