Mechanistic analysis

We can consider the hydroboration step as though it involved borane (BH3) It sim phfies our mechanistic analysis and is at variance with reality only m matters of detail Borane is electrophilic it has a vacant 2p orbital and can accept a pair of electrons into that orbital The source of this electron pair is the rr bond of an alkene It is believed as shown m Figure 6 10 for the example of the hydroboration of 1 methylcyclopentene that the first step produces an unstable intermediate called a tt complex In this rr com plex boron and the two carbon atoms of the double bond are joined by a three center two electron bond by which we mean that three atoms share two electrons Three center two electron bonds are frequently encountered m boron chemistry The tt complex is formed by a transfer of electron density from the tt orbital of the alkene to the 2p orbital... 

The mechanistic analysis of the rate of polymerization and the fact that the separate constants individually follow the Arrhenius equation means that... 

This chapter has a mechanistic emphasis designed to achieve a practical result. By understanding the mechanisms by which alkyl halides undergo nucleophilic substitution, we can choose experimental conditions best suited to cariying out a particular- functional group transfonnation. The difference between a successful reaction that leads cleanly to a desired product and one that fails is often a subtle one. Mechanistic analysis helps us to appreciate these subtleties and use them to our advantage. 

Damjanovic, A. Mechanistic Analysis of Oxygen Electrode Reactions 5... 

Thome et al. (2004) and Dupont et al. (2004) proposed the first mechanistic analysis for vaporization in a micro-channel, with a three-zone flow boiling model describing... 

Wallace VC, Blackbeard J et al (2007a) Pharmacological, behavioural and mechanistic analysis of HIV-1 gpl20 induced painful neuropathy. Pain 133(l-3) 47-63 Wallace VC, Blackbeard J et al (2007b) Characterization of rodent models of HIV-gpl20 and anti-retroviral-associated neuropathic pain. Brain 130(Pt 10) 2688-2702 Wechsler AF, Ho DD (1989) Bilateral Bell s palsy at the time of HIV seroconversion. Neurology 39(5) 747-748... 

The reaction between hydrogen and oxygen leads to the formation of water. This reaction has extended explosive regimes with respect to the p,T,c-parameters. A mechanistic analysis of the elementary reactions is available and the explosion mechanisms are imderstood in detail. Accordingly, this reaction serves well as a model for other dangerous processes in the explosive regime such as many oxidations with pure oxygen. 

A Powerfnl Methodology for Streamlining Mechanistic Analysis of Complex Organic... 

V Srinivasan, W Higuchi, S Sims, A Ghanem, C Behl. Transdermal iontophoretic drug delivery Mechanistic analysis and application to polypeptide delivery. J Pharm Sci 78 370, 1989. 

Not every excess acidity mechanistic analysis has been an outstanding success. For instance, several enolization studies have used this technique. The enolization of acetophenone was one of the reactions originally studied by Zucker and Hammett 146 their sulfuric acid rate constant data, obtained by iodine scavenging (the reaction is zero-order in halogen), was used in an excess acidity analysis,242 together with additional results obtained for some substituted acetophenones (using bromine scavenging).243... 

Mechanistic analysis, perspectives in modem voltammetry basic concepts and, 32, 1... 

Voltammetry, perspectives in modern basic concepts and mechanistic analysis, 32, 1 Volumes of activation, use of, for determining reaction mechanisms, 2, 93... 

Another important contribution of transition metal-catalyzed alkyne hydrosilylation continues to be the mechanistic analysis of catalysis. As a relatively simple addition process, hydrosilylation has lent itself to extensive and thorough mechanistic analysis yet, numerous reaction pathways have now been postulated, and it is clear that many paths are possible. Importantly, principles from hydrosilylation reactions often are of use in the understanding of related, more complex transformations. Despite past achievements, much current thinking is based as much on speculation as on solid data. It is likely that continued, detailed exploration of the mechanistic underpinnings of hydrosilylation reactions will lead to new understanding and better reactions. 

A mechanistic analysis of antibody DF8-D5 showed it to cleave p-nitrophenyl carbamate [134] with kcat = 0.3 s l, Km = 120 p,M, and cat/ uncat = 300 at 14°C (Appendix entry 4.3) (Wentworth et al., 1997). This is some tenfold more active than a carbamatase antibody generated by Schultz... 

Chen LL, Chetty DJ, Chien YW (1999) A mechanistic analysis to characterize oramucosal permeation properties. Int J Pharm 184 63-72... 

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