Subject reductive elimination

Alkenylsilanes can be prepared from aldehydes and ketones using lithio(chloromethyl)trimethylsilane. The adducts are subjected to a reductive elimination by lithium naphthalenide. This procedure is stereoselective for the E-isomer with both alkyl and aryl aldehydes.82... 

The cis/trans isomerization of platinum(II) complexes is a subject which will be discussed in some detail when the halide (Group VII) complexes are covered. Nevertheless the importance of reductive elimination reactions of platinum(II) alkyl and aryl complexes makes it imperative that this reaction be discussed here for alkyl and aryl platinum(II) compounds. 

Vaska s complex trans-IrCl(CO)(PPh ) has served as an important model for mechanistic investigation of catalytically relevant reactions such as the oxidative addition and reductive elimination of small molecules(15). The latter processes have also been the subject of some photochemical investigation. For example, the reductive elimination of H2 depicted in Equation 5, which is a relatively slow thermally activated process (k = 3.8 x 10- s l in 25° benzene solution (15)), has been shown to occur readily when the dihydride complex was subjected to continuous photolysis with 366 nm light(16). However, Vaska s compound itself was reported to be... 

The first step in this multistage reaction is the nucleophilic addition of sulfone anion 28 to aldehyde 8 (Scheme 14.6). This produces a p-alkoxysulfone intermediate 29 which is trapped with acetic anhydride. The resulting P acetoxysulfone mixture 22 is then subjected to a reductive elimination with Na/Hg amalgam to obtain alkene 23. The tendency of Julia-Lythgoe-Kocienski olefinations to provide ( )-1,2-disubstituted alkenes can be rationalised if one assumes that an a-acyloxy anion is formed in the reduction step, and that this anion is sufficiently long-lived to allow the lowest energy conformation to be adopted. Clearly, this will... 

The adduct radicals 38B can undergo direct ligand transfer from the Fe(I) complex 37B to products 32, 34, or 36 and regenerate catalyst 37A. Alternatively, it was proposed that 38B couples with the Fe(I) metal center 37B to an organoiron(II) species, which would be subject to reductive elimination. 

Reduction of 5,6/3-dibromo-5a-cholestan-3-one (128) by sodium borohydride in ethanol is subject to steric effects, giving cholest-5-en-3a-ol (130) as the main product. The 3a-hydroxy-5a,6/3-dibromide (129) is thought to be formed first and to suffer reductive elimination of the bromo-substituents with participation by the 3a-hydroxy-group.135 This convenient route to the 5-en-3a-oI is competitive in yields with some older routes. 

A second important reaction of L-AuR species is the oxidative addition (see Oxidative Addition) of halogen or alkyl halides, which leads, at least in a first step, to organo(dihalo)gold(IIl) or diorgano(halo)gold(III) products. The structures are transformed from linear to square planar, and therefore cis and trans isomers are possible. The products may undergo secondary reactions and/or become subject to a reductive elimination (see Reductive Elimination) of other substituent combinations (equations 41 and 42). ... 

The exact nature of the complex from which the final reductive elimination occurs remains subject to speculation. The involvement of a five-coordinate nickel complex RNiLsCN-A appears likely, based on the observation that reductive elimination of benzonitrile from PhNi(Et3P)2(CN) is promoted by adding triethyl phosphite, and that reductive elimination of propionitrile from EtNi[P(0-o-tolyl)3](C2H4)(CN) is first order in triaryl phosphite concentration. ... 

NHC-TM complexes can be involved in redox processes, especially reductive elimination, leading to the cleavage of the NHC-TM bond and so to the decomposition of the complex. This subject has been comprehensively reviewed by Cavell and McGuinness. ... 

A variety of a-substituted ketones (a-halo, -hydroxy, -methoxy and -amino) have been converted into alkenes by reductive elimination. Obviously, this approach, depends not only on the feasibility of a-functionalization but also on the ability to introduce the a-substituent regioselectively. a-Halo ketones, which are readily prepared from the starting ketone," have been subjected to reductive elimination conditions to afford the desired alkenic products. For example, in the preparation of ( )-eriolanin (Scheme 5)," the protected dihydroxy keto ester is treated sequentially with LDA and Br to afford the a-bromo... 

The deoxygenation of oxiranes with metals or metal-containing compounds has been the subject of wide-ranging investigations. Nonstereospecific reductive elimination has been described with Cr complexes (Eq. 101). ... 

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