Takeda reaction

The current paradigm for B syntheses came from the first report in 1957 of a synthesis of pyridines by cycloaddition reactions of oxazoles (36) (Fig. 5). This was adapted for production of pyridoxine shordy thereafter. Intensive research by Ajinomoto, BASF, Daiichi, Merck, Roche, Takeda, and other companies has resulted in numerous pubHcations and patents describing variations. These routes are convergent, shorter, and of reasonably high throughput. 

Mortars of this system are prepared by blending ignited magnesium oxide, ADP and STPP with a filler, normally quartz sand. On mixing with water a cementitious mass is formed. The reaction has been studied by a number of workers Kato et al. (1976), Takeda et al. (1979), Neiman ... 

Kitadai, K., Takahashi, M., Takeda, M., Bhargava, S.K., Priver, S.Fl. and Bennett, M.A. (2006) Synthesis, structures and reactions of cyclometalated gold complexes containing (2-diphenylarsino-n-methyl)phenyl (n = 5, 6). Dalton Transactions, (21), 2560—2571. 

Various techniques have been used for the determination of oligomers, including GC [135], HPLC [136-138], TLC for polystyrene and poly a-methyl-styrene [139] and SEC for polyesters [140,141]. GC and PyGC-MS can also profitably be used for the analysis of the compositions of volatile products formed using different flame retardants (FRs). Takeda [142] reported that volumes and compositions of the volatile products and morphology of the char were affected by FRs, polymers (PC, PPE, PBT) and their reactions from 300... 

Michael addition has been shown to lead to useful building blocks. According to a publication by Johnson and coworkers, highly functionalized unsymmetrical malonic acid derivatives are accessible in this way [268]. Moreover, as described by Takeda and coworkers, substituted four- to six-membered carbocycles 2-507 can be prepared starting from 2-504 by reaction with PhLi via the intermediates 2-505 and 2-506 (Scheme 2.115) [269]. 

The novel [6+2] annulation approach developed by the Takeda group has also been included in a threefold anionic/pericyclic process (Scheme 2.149) [340]. The reaction leads to functionalized eight-membered rings 2-659 in a highly stereoselective manner, starting from acylsilanes 2-656 and 3-(trimethylsilyl)vinyl-lithium (2-657). After 1,2-addition and 1,2-Brook rearrangement, the cyclobutane 2-... 

Mori M, Itoh H, Mori N, Abe T, Yamamoto O, Takeda Y, and Imanishi N. Reaction between alkaline earth metal doped lanthanum chromite and yttria stabilized zirconia In Badwal SPS, Bannister MJ, and Hannink RHJ. Science and Technology of Zirconia V. Lancaster, PA Technomic Publishing Co., 1993 776-785. 

Apart from the tandem metathesis/carbonyl o[efination reaction mediated by the Tebbe reagent (Section 3.2.4.2), few examples of the use of stoichiometric amounts of Schrock-type carbene complexes have been reported. A stoichiometric variant of cross metathesis has been described by Takeda in 1998 [634]. Titanium carbene complexes, generated in situ from dithioacetals, Cp2TiCl2, magnesium, and triethylphosphite (see Experimental Procedures 3.2.2 and 3.2.6), were found to undergo stoichiometric cross-metathesis reactions with allylsilanes [634]. The scope of this reaction remains to be explored. 

Eor reaction with allylic sulfides see (a) T. Takeda, S. Ogawa, N. Ohta, T. Eujiwara, Chem. Lett. 1987, 1967. For reaction with allylic acetates see (b) J. M. CuERVA, E. Gomez-Bengoa, M. Mendez, A. M. Eghavarren,/. Org. Chem. 1997, 62, 7540. 

One of the first such kinetic studies of a perovskite mixed conducting electrode was reported by Ohno and co-workers in 1981, who found Lai /la/IoOs-a to have better kinetic properties than Pt as an SOFC cathode at 1000—1100 °C. °° A number of other JiepomOKizeo of general formula Lai jSr rMOs a (M = Cr, Mn, Fe, Co) were later studied by Takeda et al. ° To avoid reaction of the perovskites with the YSZ... 

Co-limited kinetics with a significant utilization region. As with platinum, the model predicts that the chemical portion of the reaction will be co-limited by molecular dissociation and transport. Values of k calculated from the model for the analyzed conditions vary from 0.4 to 20 gvc depending on Pq2 temperature, and electrode surface area, with typical values in the 3—5 gm range. This result indicates that a significant portion of the electrode surface is active for oxygen reduction, which explains Takeda s (and other s) observation that the performance of LSG electrodes on YSZ improves with thickness up to a... 

Kano, N. Kawashima, T. The Peterson and Related Reactions in Modem Carbonyl Olefination Takeda, T. (ed.), Wiley-VCH Weinheim, Germany, 2004, 18—103. (Review). 

Takeda et al. [104] found that the steady-state irradiation of A-octadecyl 6,8-dinitro-BlPS resulted in the formation of the closed form. This is in agreement with the femtosecond studies. However, the fade reaction showed three components when monitored at 500 nm in 1,2-dichloroethane. The first component was manifest as a bleach that occurred within the instrument response time of 25 nsec. This was followed by two longer components with 240-nsec and 3.4 psec lifetimes. The spiropyran ring-closed form evolved with two exponential components with lifetimes of 620 nsec and 4 p-sec. The Af-octadecyl group may affect the outcome compared to the A-methylated form. 

The IR, NMR, and NMR spectra of this material are identical with those for distilled geranyl chloride (bp 49-51 C at 0.2 mm). Distillation on a small scale significantly reduces the yield, and there is no improvement in the yield of the phosphorylation reaction using distilled material. A synthesis of geranyl chloride was reported earlier in this series. We find, however, that the procedure of Corey, Kim, and Takeda is more convenient. 

The groups of Burczyk, Takeda, and others have made thorough studies of cyclic acetals, such as 1,3-dioxolane (five-membered ring) and 1,3-dioxane (six-membered ring) compounds, illustrated in Fig. 13. They are typically synthesized from a long-chain aldehyde by reaction with a diol or a higher polyol. Reaction with a vicinal diol gives the dioxolane [40-42] and 1,3-diols yield dioxanes [43,44]. 

Ephritikhine, M. Villiers, C. The McMurry Coupling and Related Reactions. In Modem Carbonyl Olefination-, Takeda, T., Ed. Wiley-VCH ... 

The Wittig reaction efficiently olefinates aldehydes and ketones, but not esters or amides. Several early-transition-metal approaches have been taken to this problem. Recently, Takeshi Takeda of the Tokyo University of Agriculture and Technology reported (Tetrahedron Lett. 44 5571,2003) that the titanocene reagent can effect the condensation of an amide 10 with a thioacetal 11 to give the enamine 12. On hydrolysis, 12 is converted into the ketone 13. When the reaction is intramolecular, reduction proceeds all the way, to give the pyrrolidine IS. 

We have already explained that compounds like 101 are unstable and cyclise rapidly to the lactam. So the workers at Takeda used the lactam 102 as the starting material. Opening the lactam with NaOH gave the anion 103 of 101 that added to 100 to give 99 and hence that aldol product 98 in base. Cyclisation to a seven-membered ring is preferred to intermolecular reactions. 

Takeda et al.249 analyzed the branched products made in vitro from amylose by the BE isoforms Isoamylase was used to debranch the products of each reaction. BEIIa and BEIIb were very similar in their affinity for amylose and the size of chain transferred. 

Toda, J., Niimura, Y., Takeda, K., Sano, T., and Tsuda, Y. (1998) General method for synthesis of erythrinan and homo-erythrinan alkaloids (1) synthesis of a cycloerythrinan, as a key intermediate to erythrina alkaloids, by Pummerer-type reaction. Chemical e[ Pharmaceutical Bulletin, 46, 906-912, and literature cited therein. 

Takeda and coworkers showed that the reaction of a silylmethyllithium with a halo-methyloxirane gave the corresponding cyclobutane derivatives via a 1,4-silyl migration of the initial lithium alkoxide followed by an intramolecular nucleophilic substitution of the resulting carbanion (equation 151)370. 

Formation of mortars and ceramics using ammonium drhydrogen phosphate has been studied by several investigators (Kato et al. [28], Takeda et al [29], Abdelrazig and Sharp [17], Popovics et al [21], Abdelrazig et al. [19], and El-Jazairi [20]). As shown in Table 9.1, the main products of reaction of calcined MgO with ammonium drhydrogen phosphate are struvite and schertelite. In the presence of sufficient water, the latter converts to struvite by the reaction... 

The synthesis of benzomorphans substituted in the 11-position from a 2-tetralone (Scheme 4.2, p. 157) involves either thionyl chloride dehydration of an 11-methylcarbinol (13a)(9) or a pyrolysis of the corresponding acetate perchlorate (136)methylene derivative (14). Carbocation-mediated processes in bridged compounds of this type are likely to give rearrangement byproducts. Kugita and Takeda(124) isolated from the thionyl chloride route an unstable chloride (203), and the indenotetrahydropyridine (204). Other reports(30 96a,125) of unidentified products from these reactions resulted in an investigation 126 127 of both pathways (Scheme 4.20). 

McMurry coupling, Tebbe reagent, Petasis reagent and Takeda reagent) and catalytic alke-nation of aldehydes and ketones plus the related reactions in each case. 

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