Addition reactions rearrangements

However, in an intriguing reaction promoted by the para-nitro groups of the aryl-sulphone (1) (Scheme 6.25), the initial Michael adduct derived from acrylic esters produces the diarylpropanoic esters (2), together with the diesters (3) (from methyl or ethyl acrylate) [39]. A similar addition-rearrangement reaction has been observed with l-aryl-2-(4-nitrobenzenesulphonyl)ethanones [40]. Additionally, reaction of the sulphonylethanone with two equivalents of the acrylic ester produces a 4-hydroxy-1,4-diarylcyclohexane-1,3-dicarboxylate. 

The photochemically induced addition of bulky disilanes to C6o has already been discussed in Section IV.A.l.h, as it affords the unusual inherently chiral 1,16-addition pattern (( )-72, Figure 1.20). In this reaction some phenyl-substituted disilanes give rearranged adducts of the type ( )-73 (Figure 1.20).197,404 Further [60]fullerene derivatives with stereogenic centers in the addends were obtained in photoinduced addition-rearrangement reactions with 3,4-bis(alkylidene)-l,2-disilacyclobutanes 405 and with octaaryl-substi-tuted cyclotetrasilanes and -germanes406... 

Cycloaddition reactions of trilluoroacetaldehyde occur in the presence of a Lewis acid and the competitive ene addition-rearrangement reaction to give 2 the reactions are sensitive to the acid and to the diene. 

Raasch, M.S. Heteroatom participation during addition-rearrangement reactions of 2-thia-and 2-azanorbomenes. J. Org. Chem. 1975, 40(2), 161-172. 

Table 3 Ring Expansion of Ketones by Se-based Addition-Rearrangement Reactions... 

Scheme 91 Addition-rearrangement reactions of furan derivatives with halogenated thiophene 1,1-dioxides [101]...

Scheme 93 Addition-rearrangement reactions of 2,5-disubstituted thiophene 1,1-dioxides with 2,5-disubstituted furans [116]...

A chiral quaternary carbon center via an addition-rearrangement reaction of 3,3-disubstituted allyl morpholine (61) and benzyloxyacetyl chloride (56) was successfully constructed with 300 mol% of chiral Mgl2 (60) complex, and the corresponding Claisen adduct (62) was obtained in 97% ee and 94 6 syn anti selectivity (Scheme 4.18). 

In the past decade, a large number of palladium-catalyzed domino reactions has emerged. In general, three modules are necessary a starter, one or more relay(s), and a terminating step—the terminator (Scheme 5-202). In addition, rearrangement reactions (e.g., cyclopropylmethyl-homoallyl rearrangement) are possible additional modules. The... 

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