Iodocompounds are highly attractive as potential intermediates for the synthesis of various organic and macromolecular molecules because of the ability of the iodine atom to be a good leaving atom. In addition, they are efficient transfer agents in radical polymerization. In fact, the ability of the iodine atom to transfer onto growing macromolecular chains allowed the development of such compounds. An important class of iodocompounds employed as chain transfer agents (CTAs) are the fluorinated iodocompounds, R FI. These compounds could be obtained in good yield by simple addition of either HI or ICl onto fluorovinylic monomers. These fluorinated CTAs enabled both initiation of the polymerization under UV, thermally or in the presence of redox catalysis, and transfer of the iodine atom onto the growing chains. Oligomers of low molar masses could then be obtained. Then, in the late 1970s, Tatemoto 1 pened the route to the iodine transfer polymerization (ITP). Hence, by using an initiating radical, iodofluorocompounds could enter in a controlled process, based on a degenerative transfer (DT). This real breakthrough was first realized with fluoroolefin monomers but was rapidly extended to other common nonhalogenated vinyl monomers. For specific applications, nonfluorinated CTAs were preferred. Some iodoalkanes, such as iodoform, were then investigated in the ITP process. Recently, reverse iodine transfer polymerization (RITP), another DT process, was discovered by us and is based on the use of molecular iodine. It was thus of interest to deeper summarize the synthesis and the use of iodinated derivatives involved in telomerization, ITP, and RITP, and these are the objectives of this review, divided in four main parts. The first part reports the syntheses of such iodocompounds, fluorinated and nonfluorinated ones. The structural requirements are also investigated for further efficient transfer reactions. The following parts describe their uses in several radical processes, i.e., telomerization, ITP, and RITP. A wide range of vinyl monomers (halogenated and nonhalogenated) have been involved in these radical techniques. Then, syntheses of well-architectured copolymers (especially block * To whom correspondence should be addressed. Tel: (0033)4 67 14 43 01. Fax: (0033)4 67 14 72 20. E-mail: bernard.boutevin@enscm.fr. 3936 Chem. Rev. 2006, 106, 3936−3962

Use of iodocompounds in radical polymerization.

The solvent dependence of enzyme specificity

Biologically reversible phosphate-protective groups.

Lipase-catalyzed transesterification in organic solvents: Applications to the preparation of enantiomerically pure compounds

Publisher Summary This chapter illustrates the general base and nucleophilic catalysis of ester hydrolysis and related reactions. Displacement reactions at the carbonyl carbon are more facile than at saturated carbon because: (1) the carbonyl carbon has a sizeable, partial positive charge due to the polarization of the electrons in the carbonyl group towards the oxygen, making nucleophilic attack at this center easier, (2) in carboxylic acid derivatives containing leaving groups of low basicity, the main energy barrier in a displacement reaction is the addition of the nudeophile to the carbonyl bond, which involves the breaking of the relatively weak carbonyl π-bond. In contrast, displacement reactions at saturated carbon involve the more highly energetic process of making and breaking of carbon σ-bonds, (3) the reaction center at the trigonal carbonyl carbon is less sterically hindered than at the sp3 hybridized saturated carbon. The entering group attacks the carbonyl carbon in the direction perpendicular to the trigonal plane that is at the carbon p-orbital, such that maximal overlap of the bonding orbital of the nucleophile with the carbon p orbital is possible.

General Base and Nucleophilic Catalysis of Ester Hydrolysis and Related Reactions

Porcine pancreatic lipase-catalysed transesterifications of 2,2,2-trifluoroethyl butyrate with racemic 2-octanol and 1-phenylethanol have been studied in different organic solvents. Solvent hydrophobicity (log P -1.1 to 3.3) has only a minor effect on the reaction rate. Independently of the solvent used as the reaction medium, both (R)-2-octyl and (R)-1-phenylethyl butyrates were obtained in high optical purity (ee greater than 90%). Candida cylindracea lipase is active only in the most hydrophobic solvents studied.

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Solvent effects in lipase-catalysed transesterification reactions.

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The Preparation of alpha-Haloalkyl Esters.

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Kinetics of the Neutral Hydrolysis of Chloromethyl Chloroacetate.

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The Preparation of alpha-Halogeno-sec.-alkyl Esters of Aliphatic Acids.

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Mechanism of the grignard addition reaction part 10, kinetics and deuterium isotope effects in the reaction of isobutylmagnesium bromide with benzophenone

Erkki K. Euranto

Papers

Solvent effects in lipase-catalysed transesterification reactions.

The Preparation of alpha-Haloalkyl Esters.

Kinetics of the Neutral Hydrolysis of Chloromethyl Chloroacetate.

The Preparation of alpha-Halogeno-sec.-alkyl Esters of Aliphatic Acids.

Mechanism of the grignard addition reaction part 10, kinetics and deuterium isotope effects in the reaction of isobutylmagnesium bromide with benzophenone