Matsumoto scheme

The observation by Matsumoto et al. (see 4.3.1.4) that significant amounts of head addition occur in polymerization of simple ally] monomers brings into question the origin of the small amounts of six-membered ring products that arc formed in cyclopolymerization of simple diallyl monomers (Scheme 4.14). If the intcrmolecular addition step were to involve head addition, then the intramolecular step should give predominantly a six-membered ring product (14) (by analogy with chemistry seen for 1,7 dienes - see 4.4.1.4). Note that the repeat units 14 and 16, like 12 and 17 are the same however, they are oriented differently in the chain. 

Matsumoto et al. reported some reactions of diruthenium complexes containing a bridging disulfide ligand with unsaturated compounds such as olefins and ketones [135]. These diruthenium complexes show unique reactivities towards double-bond systems since the S-S bond has some double bond character from the contribution of the canonical structure B in Scheme 36. 

Until now examples for catalytic reactions involving ferrates with iron in the oxidation state of -l-3 are very rare. One example is the hexacyanoferrate 8-catalyzed oxidation of trimethoxybenzenes 7 to dimethoxy-p-benzoquinones 9/10 by means of hydrogen peroxide which was published by Matsumoto and Kobayashi in 1985 [2]. Using hexacyanoferrate 8 product 9 was favored while other catalysts like Fe(acac)3 or Fe2(S04)3 favored product 10 (Scheme 2). The oxidation is supposed to proceed via the corresponding phenols which are formed by the attack of OH radicals generated in the Fe/H202 system. 

An example of a cyclotetrasilane dianion was recently reported by Matsumoto s group. This 1,3 dianion 77 K2 was prepared by reduction of the corresponding 1,3-dibromo precursor with potassium (Scheme 2.70). Although the Si4 ring of... 

Using 1,4-dilithiobutadiyne and /-Pr2ClSiSiCl/-Pr2, Matsumoto et al. have prepared ryc/ >-[(disilanylene)(buta-diyne)]s 272-274 that contain 12-, 18-, and 24-membered rings, and consist of alternating sequences of disilane and butadiyne units (Scheme 39).362... 

A base-mediated condensation of an isocyanide and an isothiocyanate gives 4,5-disubstituted thiazoles, as first reported by Matsumoto et al. in 1982 [73]. In subsequent work by Solomon et al., a regioisomeric imidazole was observed as a side-product due to the flexibility of the route that allows facile introduction of a substituent on the exocyclic nitrogen atom [74]. Baxendale et al. [75] explored this reaction under microfiow conditions (Scheme 33). 

In the first total synthesis by Matsumoto and co-workers (475,476), (-1-)-benzoylpedamide (536) (478,479) was prepared through a new, remote-controlled asymmetric induction (Scheme 68). An optically active acetal ketone... 

Zn(BH4)2 reduction and phenylselenation. The methyl ester of 582 was selectively hydrolyzed hy PrSLi treatment to yield (-t-)-selenoacid (569) (Scheme 71). The total synthesis of (+)-pederin (147) from (-t-)-536 and (+)-569 was accomplished in a manner similar to Matsumoto s. 

The naphthyridine core of GEM 122 has not been reported in the papers concerning it however, the standard Grohe-Heitzer sequence described earlier in the chapter will produce the required template (Bouzard et al., 1992 Matsumoto et ah, 1985 Mich et al., 1987 Sanchez et ah, 1988 Shin et al., 2004). The reaction sequence opened with hydrolysis of arylnitrile 115 to afford carboxylic acid 116 in high yield (Scheme 4.22) (Matsumoto et al., 1985). The carboxylic acid was then converted to the acid chloride, which was treated with diethyl ethoxymagnesiummalonate to yield an intermediate nico-tinoylmalonate 118. This intermediate underwent decarboxylation in the presence of... 

The synthesis of 4,6-dimethyl[l,2,5]oxadiazolo[3,4- pyrimidine-5,7-dione was reported by Matsumoto and Takahashi starting from 6-chlorouracil 95 (Scheme 71) <2002T10073>. Displacement of the chlorine substituent... 

However, the lanthanide p-diketonates shown in scheme 4 cannot be used as labels, since there is no active binding group on the p-diketonate ligands and these complexes are not very stable with stability constants in the order of 103-106 only, therefore the complexes dissociate in highly diluted solutions and the luminescence intensity decreases. Recently, three chloro-sulfonylated tetradentate p-diketones were synthesized by Yuan and Matsumoto (1996,1997) and Yuan et al. (1998a, 1998b) (scheme 5). They differ from other p-diketones, because the emission intensity of their Eu3+ complexes is not weakened by the presence of the sulfonyl... 

On an industrial scale, methane, the main component of natural gas, can easily be converted to formaldehyde. An efficient catalytic condensation of formaldehyde to dihydroxyactone or glycolaldehyde would thus provide a route to C2- and C3-chemicals from methane. The tria-zolin-5-ylidene 94 turned out to be a powerful catalyst for the conversion of formaldehyde (95) to glycolaldehyde (96) in the formoin reaction (Teles et al. 1996). This reactivity is a useful complement to the catalytic properties of thiazolium salts which mainly afford 1,3-dihydroxy acetone as product (Scheme 23) (Castells et al. 1980 Mat-sumoto and Inoue 1983 Matsumoto et al. 1984). As triazolium ylides are much more stable than thiazolium ylids, the elimination of glycolaldehyde occurs faster than the addition of the third formaldehyde molecule. 

An expeditious stereospecific synthesis of the protoilludane skeleton has been actively pursued by Matsumoto s group. In his first approach (Scheme 42),307 bicyclooctanone 274 was smoothly elaborated in classical fashion. Using a five-step sequence to effect a 1,2-carbonyl transposition with retention of a hydroxyl group at the original carbonyl site, these workers then prepared 275. Oxidation of this intermediate followed by end acetylation afforded 276. When this enone was irradiated... 

Ladder silsesquioxane polymers are very unique in the polymer family since they can be considered as an intermediate structure between a ID macromolecular chain and a 2D lamellar structure (Scheme 6). Indeed, theoretically, polysilses-quioxanes can adopt such structures. However, their preparation in high yield and leading unambiguously to the precise ladder structure is very recent although they have been postulated frequently in the past. Matsumoto et al. succeeded in their... 

Matsumoto and Tamura (at Kuraray Co.) have demonstrated that the combination of simple bis(diphenylphosp-hino)alkane ligands and PPhs has a very positive effect on catalyst stabihty and the reduction of unwanted side reactions. This is most evident in the hydroformylation of a reactive alkene substrate such as allyl alcohol. The use of HRh(CO)(PPh3)2 in the presence of excess PPhs leads to relatively rapid catalyst deactivation to unidentified species. The addition of just over 1 equivalent of dppb, for example, leads to a stable, active hydroformylation catalyst. Use of dppb either by itself, or in quantities higher than 2 equivalents, leads to catalyst deactivation and/or poor activities and selectivities. ARCO Chemical Co. licensed the Kuraray technology to build the first conunercial plant (1990) for the hydroformylation of allyl alcohol to produce 1,4-butanediol (Scheme 11). 

It is not exactly understood how the mixed ligand Rh/dppb/PPh3 catalyst system functions. Matsumoto proposed that the arm-on, arm-off equilibrium shown in Scheme 12 is operational. A species such as (5) would function much like a normal HRh(CO)(PPh3)2 catalyst, but the ability to reform the chelate to form a slightly more electron-rich complex (6) would tend to inhibit alkene isomerization and/or degradation reactions which require 16e unsaturated species. P NMR studies of Rh/chelating phosphine complexes indicate that a variety of species can form, the most dominant of which are... 

Formolysis of (264) produces the formate ester of (259) and (265) in 66% and 20% yield respectively the latter hydrocarbon is related to the pentalane class of sesquiterpenoids (see below). A study of this rearrangement, again using a deuteriated substrate, provided evidence for the pathway outlined in Scheme 38. Matsumoto et have also studied the mechanism of formation of the two tricyclic ethers (257) and (260) [with Hg(OAc)2] and the three tricyclic ethers [with Hg(N03)2] derived from humulene after NaBD4 work-up. Under these conditions the five deuteriated products are (266)—(270) respectively. The... 

Matsumoto and Tomioka examined chiral ketone 59 containing the l-aza-7-oxabicyclo[3.5.0]decane skeleton and its C2-symmetric analog 60 as catalysts in the asymmetric epoxidation of phenylcyclohexene and phenyldihydro-naphthalene (Scheme 23) in both cases, excellent yields of the oxiranes were obtained with good ee s <2002TL631>. 

Matsumoto and coworkers incorporated poly(A -(hydroxyphenyl)maleimides) into composite materials with phenol-formaldehyde resins. Poly(iV-(4-hydroxyphenyl)malei-mide) has been shown to form miscible blends with phenolic resins and, after crosslinking, produces composites with good thermal and chemical stability. The hardening or crosslinking agent most commonly used is hexamethylenetetramine (HMTA), to form an insolnble and infusible three-dimensional polymeric network (Scheme 29). 

Matsumoto et al. have reported the first example of a diastereoselective nitro-aldol reaction of optically active A,(V-dibenzyl a-amino aldehydes 150 with nitroalkanes 151 under high pressure without a catalyst (Scheme 7.38). The reactions occurred at 0.8 GPa (room temperature, 12h) and gave mixtures of diastereomers 152 and 153 in good yields and with high optical purity under atmospheric pressure 150 did not react with 151. Very high diastereoselectivity (152/153 = 99) was observed in the reaction of 150a with 2-nitropropane (151c). 

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