Reactions Murahashi

Triphenylphosphine-Diethyl azodicar-boxylate-Lithium halides, 332 Mukaiyama aldol reaction 1-Methoxy-l, 3-bis(trimethylsilyloxy)-l, 3-butadiene, 178 Tin(II) chloride, 298 Titanium(IV) chloride, 304 Trityl perchlorate, 339 Murahashi reaction N,N-Methylphenylaminotributylphos-phonium iodide, 191... 

Beller later reported that a dimeric Pd/IMes complex (1) furnishes similar yields, but in a shorter time (typically 1 h), as compared with Pd/PCy3 [33]. Another NHC ligand, IPr, was also investigated, but it was considerably less effective. Entries 6-9 of Table 8 provide a sampling of Kumada-Murahashi reactions that are catalyzed by Pd/IMes. Esters (entry 7) and imides (entry 9) are compatible with this second-generation method. 

For a recent example of an iron-catalyzed Kumada-Murahashi reaction of alkyl halides... 

These reactions are Moritani-Fujiwara reactions, Heck reactions, Mizoroki-Heck reactions, Kumada-Tamao-Corriu reactions, Murahashi reactions, Eto-Hagihara reactions, Negishi reactions, Migita-Kosugi-Stille reactions, Suznki-Miyanra reactions, and Hiyama reactions. 

Kummeter et al. [34] successfully employed this type of Alder-ene cycloisomerization as an entry to a sequentially Ir-catalyzed cycloisomerization-Murahashi reaction sequence in a one-pot manner, where the intermediate aldehyde arising from the Alder-ene tautomerization step was condensed with cyano acetic esters without addition of acids or bases, furnishing five-membered heterocycles 19 with super-Michael acceptors in the side chain (Scheme 12.10). 

Scheme 12.10 Sequentially Ir-catalyzed Alder-ene-Murahashi reaction sequence.

The synthesis of phthalimidines by dicobalt octacarbonyl-catalyzed carbonylation of Schiff bases was first described by Pritchard78 and the scope of the reaction was evaluated by Murahashi et a/.79 Later Rosenthal et al.80-83 subjected a variety of related compounds to carbonylation, and also achieved a phthalimidine synthesis directly from benzonitrile under the conditions of the oxo process.84 An example illustrating the formation of a phthalimidine is shown in Scheme 49 a comprehensive review of the scope and mechanism of reactions of this type is available.85... 

Yamamura and Murahashi (1977) have studied the crown ether-catalysed cyanation of vinyl halides under solid—liquid phase-transfer conditions (20). The reaction of /rans-/ -bromostyrene [140] with sodium cyanide in benzene,... 

Hulmes, D.I., Knight, E.I., Layzell, T.P. and Lloyd-Jones, G.C. (1999) Transition Metal-Catalysed Reactions (eds S.I. Murahashi and S.G. Davies), Blackwell Science, Oxford, UK, p. 465 ... 

Alexakis A (1999) In Murahashi SI, Davies SG (eds) Transition metal catalyzed reactions. lUPAC Blackwell Science, Oxford, p 303... 

Pd-Pd bonded moiety from the dipalladium(II) complexes is of great interest in relation to the dinuclear addition reactions discussed above. (Adapted from Murahashi et ah, 2006)... 

In 1989, a method for the peroxysilylation of alkenes nsing triethylsUane and oxygen was reported by Isayama and Mnkaiyama (eqnation 25). The reaction was catalyzed by several cobalt(II)-diketonato complexes. With the best catalyst Co(modp)2 [bis(l-morpholinocarbamoyl-4,4-dunethyl-l,3-pentanedionato)cobalt(n)] prodnct yields ranged between 75 and 99%. DiaUcyl peroxides can also be obtained starting from tertiary amines 87, amides 89 or lactams via selective oxidation in the a-position of the Af-fnnctional group with tert-butyl hydroperoxide in the presence of a ruthenium catalyst as presented by Murahashi and coworkers in 1988 ° (Scheme 38). With tertiary amines 87 as substrates the yields of the dialkyl peroxide products 88 ranged between 65 and 96%, while the amides 89 depicted in Scheme 38 are converted to the corresponding peroxides 90 in yields of 87% (R = Me) and 77% (R = Ph). 

Murahashi and co-workers (49) extensively studied the synthesis of nitrones such as 29 by a decarboxylative oxidation of proline derivatives (Scheme 12.12). However, these nitrones were primarily used in nucleophilic addition reactions rather than 1,3-dipolar cycloadditions. Others have synthesized cyclic nitrones 30 and 31 having a chiral center adjacent to the nitrogen atom (50,51). Saito and co-workers (51) applied nitrone 31 in reactions with fumaric and maleic acid... 

The amino acid derived chiral oxazolidinone 188 is a very commonly used auxiliary in Diels-Alder and aldol reactions. However, its use in diastereoselective 1,3-dipolar cycloadditions is less widespread. It has, however, been used with nitrile oxides, nitrones, and azomethine ylides. In reactions of 188 (R = Bn, R =Me, R = Me) with nitrile oxides, up to 92% de have been obtained when the reaction was performed in the presence of 1 equiv of MgBr2 (303). In the absence of a metal salt, much lower selectivities were obtained. The same observation was made for reactions of 188 (R = Bn, R = H, R = Me) with cyclic nitrones in an early study by Murahashi et al. (277). In the presence of Znl2, endo/exo selectivity of 89 11 and up to 92% de was observed, whereas in the absence of additives, low selectivities resulted. In more recent studies, it has been shown for 188 (R =/-Pr, R = H, R =Me) that, in the presence of catalytic amounts of Mgl2-phenanthroline (10%) (16) or Yb(OTf)3(20%) (304), the reaction with acyclic nitrones proceeded with high yields and stereoselectivity. Once again, the presence of the metal salt was crucial for the reaction no reaction was observed in their absence. Various derivatives of 188 were used in reactions with an unsubstituted azomethine ylide (305). This reaction proceeded in the absence of metal salts with up to 60% de. The presence of metal salts led to decomposition of the azomethine ylide. 

Palladium-catalyzed, Wacker-type oxidative cycHzation of alkenes represents an attractive strategy for the synthesis of heterocycles [139]. Early examples of these reactions typically employed stoichiometric Pd and, later, cocat-alytic palladium/copper [140-142]. In the late 1970s, Hegedus and coworkers demonstrated that Pd-catalyzed methods could be used to prepare nitrogen heterocyles from unprotected 2-allylanilines and tosyl-protected amino olefins with BQ as the terminal oxidant (Eqs. 23-24) [143,144]. Concurrently, Hosokawa and Murahashi reported that the cyclization of allylphenol substrates can be accomplished by using a palladium catalyst with dioxygen as the sole stoichiometric reoxidant (Eq. 25) [145]. 

In addition to the development of new catalysts and reaction conditions for aerobic oxidative heterocycUzation, considerable effort has been directed toward asymmetric transformations. Hosokawa and Murahashi reported the first example of asymmetric Pd-catalyzed oxidative heterocycUzation reactions of this type [157,158]. They employed catalytic [(+)-(Ti -pinene)Pd (OAc)]2 together with cocatalytic Cu(OAc)2 for the cycUzation of 2-allylphenol substrates however, the selectivity was relatively poor (< 26% ee). 

Hosokawa, Murahashi, and coworkers demonstrated the ability of Pd" to catalyze the oxidative conjugate addition of amide and carbamate nucleophiles to electron-deficient alkenes (Eq. 42) [177]. Approximately 10 years later, Stahl and coworkers discovered that Pd-catalyzed oxidative amination of styrene proceeds with either Markovnikov or anti-Markovnikov regioselectivity. The preferred isomer is dictated by the presence or absence of a Bronsted base (e.g., triethylamine or acetate), respectively (Scheme 12) [178,179]. Both of these reaction classes employ O2 as the stoichiometric oxidant, but optimal conditions include a copper cocatalyst. More recently, Stahl and coworkers found that the oxidative amination of unactivated alkyl olefins proceeds most effectively in the absence of a copper cocatalyst (Eq. 43) [180]. In the presence of 5mol% CUCI2, significant alkene amination is observed, but the product consists of a complicated isomeric mixture arising from migration of the double bond into thermodynamically more stable internal positions. 

I. Moritani, T. Hosokawa u. S.I. Murahashi, Organotransition-Met. Chem., Proc. Jpn.-Am. Semin., 1st, 273 -279 (1973) The Palladium-catalyzed Reactions for Synthesis of Amines and Benzofurans". 

El Ali, B. Alper, H. In Transition Metal Catalyzed Reactions IUPAC Monograph Chemistry for the 21st Century"-, Davies, S. G. Murahashi, S. (Ed.) Blackwell Science Oxford, 1999. 

Ikariya, T. Noyori, R. In Transition Metal Catalyzed Reactions Murahashi, S.-I, Davies, S. G., Eds. IUPAC, Blackwell Science New York, 1999 pp. 1-28. Ikariya, T. Jessop, P. G. Noyori, R. Japan Tokkai Patent 5-274721, 1993. 

Heiss, C. Marzi, E. Schlosser, M. Buttressing effects rerouting the deprotonation and functionalization of 1,3-dichloro- and 1,3-dibromo-benzene. Eur J. Org. Chem. 2003, 4625 -629. Murahashi, S.-I. Naota, T. Tanigawa, Y. Palla-dium-phosphine-complex-catalyzed reaction of organometallic compounds and alkenyl halides (Z)-/j-[2-( N,. -di rn ethyl ami no) pheriyl]-styrene. Org. Synth. 1990, Coll. Vol. VII, 172— 176. 

Murahashi, S.-I. Tamba, Y. Yamamura, M. Yoshimura, N. Reactions of cyclometalated Pd complexes with organolithium compounds or Grignard reagents. Selective ortho alkylation and arylation of benzaldehydes, azobenzenes, and tertiary benzylic amines. J. Org. Chem. 1978, 43, 4099-4106. 

Drandarov, K. Hesse, M. Lithium and proton templated co-polyazamacrolactamization, new general routes to macrocyclic polyamines. Tetrahedron Lett. 2002, 43, 7213-7216. Murahashi, S.-L Yoshimura, N. Tsumiyama, T. Kojima, T. Catalytic alkyl group exchange reaction of primary and secondary amines. 

Nagashima H (2004) Ruthenium-promoted radical reactions. In Murahashi S-i (ed) Ruthenium in organic synthesis. Wiley-VCH, Weinheim, p 333... 

Interestingly, the reaction of active methylene compounds having a nitrile group with a,/l-unsaturated carbonyl compounds give Michael adducts without contamination by the corresponding aldol products (Eq. 61) [89-92]. Murahashi and coworkers [89-91] proposed that the addition of the C-H bond to a low-valent ruthenium constitutes the initial step. Recently, Takaya and Murahashi [94] applied their aldol and Michael addition reactions to solid-phase synthesis using polymer-supported nitriles. 

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