CBS reaction

Chapter 11, Reactions of Alkyl Halides Nucleophilic Substitutions and Eliminations—A discussion of the El cB reaction has been added to Section 11.10, and a new Section 11.11 discusses biological elimination reactions. 

Table 1 Scheme of chain-breaking (cb) reactions for different types of...

Yang H, Asplund MC, Kotz KT, Wilkens MJ, Frei H, Harris CB. Reaction mechanism of silicon-hydrogen bond activation studied using femtosecond to nanosecond IR spectroscopy and ab initio methods. J Am Chem Soc 1998 120(39) 10154-10165. 

A similar approach was employed in our laboratory for the development of molecularly imprinted catalysts for the enantio-selective reduction of prochiral ketones with borane (CBS reaction) [122]. A stable, polymerisable transition state analogue of this reaction leading to the formation of one particular enantiomer product was prepared (Fig. 4.9). After polymerisation, the template molecule can... 

The final stage u dehydration of the aldol and an El cB reaction that involves the carbonyl group as in a standard aldol reaction (Chapter 27). Another enolate must form in the same position as the last the Robinson ennelatlon meohanlsm—etaie 9 the ClcB del retion... 

The reaction occurs in an adiabatic stirred flow reactor with feed flow rate F, transient compositions ca and cb, reaction rate J, and total mass of reacting mixtures M. 

CBS Reduction of Ketones (PPG-Sipsy with Caiiery Lonza). Hydride reduction with a proline-derived catalyst (CBS reaction) was applied by Lonza to make 50 kg of an intermediate for Josiphos ligands (79,80). 

The inhibiting effect of strain on eliminative formation of the phenylsulfonyl conjugated exocyclic double bond on E cB reaction of 1-(phenylsulfonyl methyl)-1-Z-cyclopropanes increases from 1.4 to 10" as the leaving group Z becomes poorer up to 50% of the enthalpy difference between strained and unstrained products may influence the relative stabilities of the transition states involved. 

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