A Mechanistic Investigation of the Carbon−Carbon Bond Cleavage of Aryl and Alkyl Cyanides Using a Cationic Rh(III) Silyl Complex

Taw, Felicia L.; Mueller, Alexander; Bergman, Robert G.; Brookhart, Maurice

doi:10.1021/ja034468o

Cited by 124 publications

(82 citation statements)

References 14 publications

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“…Similar silyl-assisted nitrile C-C bond cleavage was reported independently by Bergman, Brookhart and co-workers using Rh [22] and Ir [23] complexes. Later, Hashimoto et al [24] and Tobiso et al [25] and their co-workers reported this type of silyl-assisted nitrile C-C bond cleavage.…”

Section: Stoichiometric C-cn Bond Cleavage Of Acetonitrile By a Silylsupporting

confidence: 83%

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Strong bond cleavage promoted by silyl group migration in a coordination sphere

Nakazawa

2011

WIT Transactions on Ecology and the Environment

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C-CN bond cleavage in organonitriles was attained in the photoreaction with HSiEt 3 in the presence of a catalytic amount of ( 5 -C 5 H 5 )Fe(CO) 2 Me. The reaction sequence was proposed, where silyl migration from Fe to N in the coordinating nitrile is a key step. DFT calculations proposed a silyl migration with small activation energy of 4.0 kcal/mol and subsequent C-CN bond cleavage on the Fe coordination sphere. N-CN bond cleavage in cyanamide (R 2 NCN) was also attained by a transition metal catalyst. A catalytic cycle was proposed where a silyl migration from a transition metal to the nitrile nitrogen is involved. An N-silylated  2 -amidino complex was isolated, which was shown to be an intermediate in the catalytic pathway.

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Section: Stoichiometric C-cn Bond Cleavage Of Acetonitrile By a Silylsupporting

confidence: 83%

“…Thus the reaction on changing the molar ratio of Et 3 SiH and MeCN was examined. Reaction of Et 3 SiH with a 10-fold molar excess of MeCN in the presence of 0.83 mol% CpFe(CO) 2 [22] systems, this catalytic system is very effective.…”

Section: Consideration Of Catalytic Cyclementioning

confidence: 99%

Strong bond cleavage promoted by silyl group migration in a coordination sphere

Nakazawa

2011

WIT Transactions on Ecology and the Environment

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“…Jesson and coworkers (21) have also documented the formation of the cyanomethyl hydride as a result of activation of acetonitrile using (dmpe) 2 M(Np)H (M ϭ Fe, Ru; Np ϭ 2-naphthyl). The scission of the COCN bond of acetonitrile has also been reported by Parkin and coworkers (22), Brookhart and coworkers (23,24), Nakazawa et al (25), and Jones and coworkers (26). Of particular interest is the work by Brookhart using a similar Cp*Rh(PMe 3 ) system (23), which is known to undergo COH bond activation in the presence of alkanes and arenes (3,27).…”

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confidence: 57%

The activation of alkyl cyanides using a rhodiumtrispyrazolylborate complex

Vetter

Rieth

Jones

2007

Proc. Natl. Acad. Sci. U.S.A.

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O rganometallic complexes of the cyclopentadienyl (Cp) and trispyrazolylborate (Tp) type have been shown to activate a variety of COH bonds in alkanes and arenes (1-9). However, studies on the activation of alkanes and arenes containing reactive functional groups have received far less attention in the literature. Hartwig and coworkers (10-12) have been successful in the hydroborylation of mono-and disubstituted arenes using transition metal catalysts. The borylation of the arene ring is believed to occur after oxidative addition of the ring COH bond without interference of reaction with the functional group. Smith (13,14) has even shown that haloarenes can be borylated and functionalized without affecting the carbon-halogen bond. Although numerous examples are presented for the functionalization of substituted arenes (15), the functionalization of alkanes containing reactive functional groups is somewhat restricted, perhaps because some of the functional groups on the alkanes are more reactive toward the catalysts and do not allow for COH activation. In addition, some functional groups (e.g., OH) are known to make the adjacent COH bonds more reactive in alkanes (16).We recently reported the activation of 1-, 2-, and 3-chloropentanes using a trispyrazolylborate rhodium complex (17). It was determined that the [TpЈRh(L)] fragment did not oxidatively cleave the COCl bond of the chloroalkane, as would have been expected given the relative bond strengths of COH (Ϸ100 kcal) vs. COCl (80 kcal) bonds (18) and the literature precedence that exists for the oxidative addition of COCl bonds to Rh(I) and Ir(I) metal systems (15,19). Surprisingly, the [TpЈRh(L)] fragment reacted exclusively with the terminal COH bonds of the alkane to give the substituted haloalkyl hydride complex. Here, we extend the investigation of the activation of hydrocarbon COH bonds to include substrates containing the nitrile functional group (OC'N).The COH bond activation of acetonitrile has been documented in the past. Teuben and coworkers (20) have reported the COH activation of acetonitrile via a -bond metathesis using Cp* 2 LnCH(SiMe 3 ) 2 . Jesson and coworkers (21) have also documented the formation of the cyanomethyl hydride as a result of activation of acetonitrile using (dmpe) 2 M(Np)H (M ϭ Fe, Ru; Np ϭ 2-naphthyl). The scission of the COCN bond of acetonitrile has also been reported by Parkin and coworkers (22), Brookhart and coworkers (23, 24), Nakazawa et al. (25), and Jones and coworkers (26). Of particular interest is the work by Brookhart using a similar Cp*Rh(PMe 3 ) system (23), which is known to undergo COH bond activation in the presence of alkanes and arenes (3,27). However, in the presence of nitriles and triphenylsilane, the complex promotes the cleavage of the COCN bond.To demonstrate the diversity of nitrile reactivity with low valent metals, our group has also investigated the reactions of aromatic, allylic, and alkyl nitriles using [(dippe)NiH] 2 (28-30). In these studies, 2 coordination of the CN bond to the Ni metal cent...

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“…Examples of such g 1 -bound aryl complexes are relatively less common in the literature [58][59][60][61][62][63][64][65][66][67][68][69][70][71][72][73]. It may be added in this context that metal mediated C-N bond cleavage, though not very uncommon, is mostly limited to strained amines and amidines [74][75][76][77][78][79], and hence there is significant interest in transition metal mediated C-N bond cleavage [80][81][82][83][84][85][86][87][88][89].…”

Section: Synthesis and Characterizationmentioning

confidence: 99%