Bond cleavage triethylsilane

A very attractive method for the dehydrogenative silylation of arenes via the C-H bond cleavage has been recently reported by Kakiuchi et al. [15]. The reaction of aryloxazolines with trialkylsilanes (mostly triethylsilane) catalyzed by Ru complexes results in the formation of ortho-silylated aryloxazolines in good-to-excellent yields (Eq. 7). 

Novel syntheses of amino acids have also employed triethylsilane C-0 bond cleavages of (V, 0-acetals. In this way, Af-methyl-amino acid derivatives are isolated in high yields from the Fmoc or Cbz protected 5-oxazolidinone precursors, using TFA and Ets SiH, or with the Lewis acid AICI3 and Et3SiH (eq 31). A one-pot preparation of (V-methyl-a-amino acid dipeptides can be accomplished from an oxazolidinone, amino acid, TFA, and Et3SiH combination. ... 

The reactions of rranj-(+)-[PtCl(SiMePh l-naphthyl )(PPhMea)2] and of its PPhg analogue with lithium aluminium hydride, triethylsilane, or thiophenol involve silicon-platinum bond cleavage. There is predominant retention of configuration at the silicon centre. A mechanism involving successive oxidative addition and reductive elimination steps, with platinum(iv) intermediates, is thought to operate for these reactions. ... 

Derivative 61 was synthesized in 71% yield by reductive bond cleavage of the corresponding 4,6-0-o-nitrobenzylidene acetal of methyl 3,4-acetyl- 5-glucoside with triethylsilane and boron trifluoride ether-ate, followed by deacetylation of the 3,4-diacetates with sodium methoxide in methanol. 

Based on the few reported examples, the pattern of ring cleavage that accompanies the ionic hydrogenation of alkylidenencyclopropanes seems to be related to the pattern and degree of substitution on both the ring and the double bond.233 Thus, treatment of l,l-dimethyl-2-methylenecyclopropane with two equivalents of triethylsilane and four equivalents of trifluoroacetic acid for 90 hours at room temperature yields 65% of 2,3-dimethylbutane (Eq. 114).229 Exposure of 1,1-dimethyl-2-isopropylidenecyclopropane to the same ratio of reactants at 50° for 16 hours produces a complex mixture containing 63% of 2,5-dimethylhexane, 18.5% of 2,5-dimethyl-3-hexene, 1.6% of 2,5-dimethyl-2-hexene, and 7% of 2,5-dimethyl-2-hexyl trifluoroacetate (Eq. 115).229... 

McMurray [151] has described the acid-assisted cleavage of the N]-C4 bond in trans 4-hydroxyphenyl p-lactams. The ring opening reaction may proceed with concomitant reduction or formation of carbon-carbon coupling products, as a function of the reagent employed. For instance, Scheme 60, treatment of 196 with 4 equivalents of triethylsilane in neat trifluoroacetic acid led to compound 197. On the contrary, treatment with anisole in trifluoroacetic acid led to compound 198. Unfortunately, no data are provided by authors regarding process yield or final diastereomeric ratio. 

The evidence that ,Z-isomerization of 92-95 proceeds by Si=Si bond rotation and not a mechanism involving silylene intermediates, produced by cleavage of the Si=Si bond followed by recombination, rests upon the fact that no trapping products consistent with the intermediacy of the corresponding diarylsilylenes could be detected upon heating the disilenes in the presence of known silylene traps such as methanol, triethylsilane or 2,3-dimethyl-l,3-butadiene. In fact, one tetraaryldisilene has been shown to isomerize by this mechanism, the 1,2-dimesityl-l,2-bis(2,4,6-tris[bis(trimethylsilyl)methyl]phenyl derivatives (E)- and (Z)-97a (equation 70)142,143. Arrhenius parameters for the thermal dissociation of (E)- and (Z)-97a to diarylsilylene 98 are listed in equation 70. 

In a one-step reaction triethylsilane and selenium form triethylsilaneselenol (769)440 (equation 399). The related hexamethyldisilaselenane (770) can be obtained from chloro-trimethylsilane and disodium selenide441 (equation 400). Alkylselenoorganylsilanes (772) are formed when halogenoorganylsilanes react with methylselenol (771) in the presence of tertiary amines422 (equation 401) or via cleavage of a Si-N bond by 771 (equation 402)422. 

Reduction of 2 with triethylsilane catalyzed by TiCU effects only cleavage of the C-O bond to give 5 in >94% de. This product is reduced to the lactam 6 by Li/NH. Unfortunately the chiral auxiliary is not recovered. 

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