Synthetic applications involving

The stoichiometric and catalytic protocols have been employed in a number of synthetic applications involving formations of one or more rings that will be discussed next. The functional group tolerance and short approaches to complex structure are especially relevant. 

Enantiomencally pure (+)- and (-)-diphenylethylenediamines have recently been used for highly stereoselective Dlels-Alder, aldol,8 allylation,9 osmylation,10 and epoxidafion11 reactions. Other synthetic applications involve enantioselective Michael addition12 and asymmetric hydrogenation.13... 

Synthetic applications involving regioselective or diastereoselective photooxygenation ene reactions, as key steps, are very common in the literature and some examples have already been reported in the previous sections. Additionally, the number of natural products... 

The synthetic applications involving tin-oxygen bonds in organic chemistry (including carbohydrates) have been reviewed in a book on the use of tin in organic synthesis [7]. 

This chapter on electrophilic heteroatom cyclizations covers reactions of carbon-carbon ir-bonds in which activation by an external electrophilic reagent results in addition of an internal heteroatom nucleophile. The general reaction is illustrated in Scheme 1. These cyclization reactions generate heterocyclic products, but many synthetic applications involve subsequent cleavage of the newly formed heterocyclic ring. 

Some synthetic applications involving an intramolecular VNS reaction have been developed.116-118... 

W. T. Brady, Synthetic Applications Involving Halogenated Ketenes, Tetrahedron 1981, 37, 2949. 

Direct interaction of the excited state with a chiral environment seems the most attractive way to create asymmetry in photoproducts, because the chiral inductor is not destroyed during the reaction. Since the pioneering work on the asymmetric isomerization of cyclopropanes in photosensitized experiments [12] was published, recent reports have shown that high selectivities can be achieved in asymmetric photosensitizations [13]. However, the most promising results for synthetic applications involve photoreactions in rigid and organized media such as chiral monocrystals or inclusion complexes. 

Synthetic applications involving the heterocycloreversion of 2-azanor-bomenes... 

The general process is illustrated by the classic hirsutene synthesis developed by Curran (Scheme 25.2). In the 1980s, Stork and Curran contributed to a rapid expansion of synthetic applications involving radical processes, which was preceded by the work of Barton, Giese and Hart, who had begun a new era for radical chemistry by introducing novel radical-featuring synthetic methods. Subsequent... 

Selective monoalkylation of Cp2ZrCl2 to form Cp2Zr(R)Cl in which R is alkyl or alkenyl is best accomplished by hydrozirconation with [Cp2Zr(H)Cl]n (1). Most synthetic applications involve the use of terminal organozirconocene complexes. The hydrozirconation reaction on carbon-carbon double or triple bonds with 1 is generally clean and gives high yields of essentially 100% ds addition products. 

While the synthetic applications involving oxidation of the various substrate types was being investigated mainly by Ishii s group [32-38] using [PWj204o] as the catalyst, other researchers have actively pursued studies aimed at an understanding of the identity of the true catalyst in these reactions [39—42]. In this context it should be... 

The two reaction channels described represent the most important steps following the generation of the initial radical cation and can be directly incorporated into synthetic applications involving silyl enol ether radical cations. Deprotonation of the radical cation is a way to conduct a ketone-enone transformation via the silyl enol ether. Other synthetic applications utilizing the radical cation or the a-carbonyl radical are coupling reactions of silyl enol ethers, intramolecular addition to double bonds, or introduction of substituents other than carbon at the a-carbonyl position, respectively. Examples for these synthetic transformations will be presented in the following sections. 

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