Giese reaction

Curran2 has reviewed recent applications of the tin hydride method for initiation of radical chain reactions in organic synthesis (191 references). The review covers intermolecular additions of radicals to alkenes (Giese reaction) as well as intramolecular radical cyclizations, including use of vinyl radical cyclization. 

In contrast to the tin hydride-mediated reaction (Giese reaction) [90], no slow addition of the chain carrier is necessary. This is easily understandable... 

C-Disaccharides.5 These disaccharides linked by a CH2 group can be prepared by an extension of the Giese reaction. Thus the radical generated from a glycosyl... 

Modified Giese reaction.6 The radical obtained by denitration of tertiary nitro compounds undergoes inter- and intramolecular reaction with activated double bonds. 

The Giese reaction has been used for reductive cyclization of a,/l-enones containing an isolated terminal double bond. Solvomercuration can be carried out selectively on the latter group. On hydride reduction, the mercurial group is reduced preferentially and undergoes addition to the enone group. Experimentally, no products resulting from prior reduction of the enone are observed. Yields of cyclized products are usually satisfactory.4... 

The combination of the catalytic method and the three-phase separation could be applied to the parallel rapid synthesis of a small library of nine compounds of type 7 using the Giese reaction (eq. 5.3). The attractive prospect from this simple experiment arises from the very efficient workup protocol, allowing facile and quantitative separation even if excess reagents... 

The reaction involves an intermediate (3-peroxy carbon free radical (c/. Giese reaction, 11, 315-316), which then displaces the silyloxy group to form an epoxide. 

Coupling of ketones with electron-deficient alkenes via a methylene group (cf. II, 315-316). This modified Giese reaction involves cyclopropanation of the silyl enol ether of a ketone, mcrcuration, and finally demercuration and coupling with an alkcnc via a radical chain reaction. 

Deoxy sugars." Branched 2-deoxy sugars can be prepared by solvomercuration of a glycal followed by the Giese reaction with an electrophilic alkene, with marked preference for formation of an equatorial substituent. 

GIESE REACTION Mercury(II) acetate. Tri- -butyltin hydride. 

Bokelmann, C., Neumann, W.P. and Peterseim, M. (1992) Investigations on the Giese Reaction Carried Out with Polymer-Supported Organotin Reagents, /. Chem. Soc.y Perkin Trans. 1, 3165-3166. 

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