Miyano reaction

As a practical example of application of this method, the Miyano reaction proved useful for the preparation of chiral binaphthyl Hoveyda-Grubbs-type catalyst 47, which finds utility in asymmetric metathesis (Scheme 8.10) [37]. This chiral complex possessing a stereogenic Ru center can be prepared in greater than 98% enantiomeric purity without resolution from optically pure binaphthalene 46 prepared by the Miyano method. Howevo", in contrast to the Meyers reaction, the Miyano reaction has so far not been employed for the total synthesis of natural products. 

The possibility of a radical mechanism is supported by the observation of the accelerating effect of molecular oxygen on the cyclopropanation. Miyano et al. discovered that the addition of dioxygen accelerated the formation of the zinc carbenoid in the Furukawa procedure [24a, b]. The rate of this process was monitored by changes in the concentration of ethyl iodide, the by-product of reagent formation. Comparison of the reaction rate in the presence of oxygen with that in the... 

Dihydro-2H-pyran-2-ones (e. g., 4-195) are valuable intermediates in the synthesis of several natural products [67]. Hattori, Miyano and coworkers [68] have recently shown that these compounds can be easily obtained in high yield by a Pd2+-catalyzed [2+2] cycloaddition of ct, 3-unsaturated aldehydes 4-192 with ketene 4-193, followed by an allylic rearrangement of the intermediate 4-194 (Scheme 4.42). In this reaction the Pd2+-compound acts as a mild Lewis acid. a,(3-unsaturated ketones can also be used, but the yields are below 20%. 

H Miyano, T Toyo oka, K Imai. Further studies on the reaction of amines and proteins with 4-fluoro-7-nitrobenzo-2-oxa-1,3-diazole. Anal Chim Acta 170 81-87, 1985. 

The first example of an asymmetric [2 + 2] cycloaddition of a ketene to an aldehyde was reported in 1994 by Miyano and coworkers [28]. They found that chiral aluminum catalysts prepared from different 3,3 -disubstituted BINOL derivatives resulted in low to modest asymmetric induction for a range of aliphatic and aromatic aldehydes. There does not seen to be a correlation between asymmetric induction and the size of the aldehyde. The data in Table 5 show that the optimum ligand for this reaction is triphenylsilyl substituted BINOL. It is curious that the catalyst prepared from this ligand and the catalyst prepared from BINOL result in opposite facial selectivity with... 

The classical Ullmann reaction has also attracted renewed interest in recent years. Miyano has prepared optically enriched binaphthyl derivatives by intramolecular biaryl coupling, as shown in equation (9). " Diastereoselectivities of up to 70% have been obtained with a binaphthol chiral auxiliary in the linking chain. Intermolecular cross-coupling is best accomplished with preformed arylcopper compounds. "... 

According to a method of Miyano and Abe AT-arylenaminones bearing an ortho-amino-substituent can be cyclocondensed to pharmaceutically useful dibenzo-l,4-dia-zepine derivatives . The same enaminones with benzoyl chloride derivatives give first the benzoylated derivative which by intramolecular condensation gave the same ring system (equation 24). An extension of this reaction to heterocyclic enaminones derived from N-substituted piperidine-3,5-diones is also known . 

Some comparisons between the yields of the Mannich reaction of enol silanes using in situ methods for preparation of the iminium salt and non in situ methods are shown in Table 9. Higher yields (20-30%) of P-amino ketones using in situ methods are seen in entries 2 and 4 but not in entry 1. Although a clear advantage of the in situ methods is not evident in these limited examples, in situ methods may be preferred from the standpoint of convenience. With aldehyde enol silanes (entry 3), the in situ method of Miyano et al is less practical due to elimination of the amino group, presumably caused by the strongly basic N,/V,/V, N -tetramethyl(methylene)diamine present in solution. 

Bosetti et al [4.29] have reported the oxidation of naphthalene by Pseudomonas fliioroscens to optically pure cA-1,2-dihydroxy-1,2-dihydronaphtalene. They reported that the MBR, after 25 h of reaction, had a production rate three times that of a batch reactor. Recently Miyano et al [4.30] reported improvement in the rate of vitamin B12 production by Propionibacterium freudenreichi using a hollow-fiber MBR. The strain used produced also propionic and acetic acid, which inhibit its activity. The authors compared the MBR with a batch reactor using a co-culture. For the batch reactor application, a second strain Ralstodia. Eutropha), which was able to metabolize partially the toxic propionic acid, was introduced into the fermentor. The experimental results of Miyano et al [4.30] showed that the MBR was much more efficient than the co-culture batch operation. 

Miyano and co-workers [75JCS(CC)760 76JCS(P1)1146] and subsequently other groups (80TL3795 83S933) reported that reactions between o-thioaniline and 1,3-dicarbonyl compounds in DMSO give the enaminones 594, which cyclize to the benzothiazines 595 in good yields. Scheme 161. 

Kumagai, H. Hasegawa. M. Miyanari. S. Sugawa. Y. Sato. Y. Hori, T. Ueda. S. Kamiyama, H. Miyano, S. Facile synthesis of / re/t-Butylthiacalix[4]arene by the reaction of p- err-Butylphenol with elemental sulfur in the presence of a base. Tetrahedron Lett. 1997, 38. 3971. 

The kinetic resolution should be considerably enhanced if a chiral dicar-boxylic acid capable of ring formation to both 6-hydroxy groups of skyrin would be applied. We selected for this purpose 6,6 -dinitrodiphenic acid dichloride (32) which can easily be obtained in both enantiomeric forms. Reaction of (+)-(R)-binaphthol 31 with racemic 32 afforded the (+)-lactone 33, [a]p +213°, whereas the unreacted acid 34 showed a negative rotation (Scheme 7). Further investigations with the optically pure reagents indicated that (+)-(R)-31 forms only a lactone 33 with (+)-(R)-32 whereas (-)-( )-31 reacts only with (-)-( )-32. The same results were obtained with tetrachlorodiphenic acid dichloride. Similar observations have recently been published by Miyano and co-workers (ref. 20) for 1,1 -binaphthyl-2,2 -dicarboxylic dichloride. 

Y. Hirata, K. Miyano, S. Sameshima, Y. Kamino, Reaction between SiC surface and aqueous solutions containing A1 ions. Colloids Surf. A 133 (1998) 183—189. 

Miyano and coworkers reported the carboxylation of fused aromatic compounds with carbon dioxide catalyzed by AlBr3 (Scheme 6.8) [10]. Although yields are moderate, the reaction proceeds regioselectively similar to the Friedel-Crafts acylation reaction. 

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