Mori transformation

The Mori transformation can be used to formally obtain an exact system of equations for quantities of interest ... 

The mechanism of the Hurd-Mori reaction has been discussed extensively in the review by Stanetty. The mechanism of the reaction was initially postulated by Hurd-Mori based on the isolation of intermediate 10. This intermediate was shown to transform into the desired thiadiazole upon heating in ethanol, either with or without acid. The reaction was thought to proceed via the four-membered intermediate 11, which would release the volatile ethylformate as a by-product. In 1995, Kobori and co-workers were able to isolate and determine crystallographically a very similar intermediate structure to 10 in their mechanistic studies of the reaction. ... 

Preparation of thiadiazoles via the Hurd-Mori cyclization has led to the synthesis of a variety of biologically active and functionally useful compounds. Discussion of reactions prior to 1998 on the preparation of thiadiazoles have been compiled in a review by Stanetty et al Recent syntheses of thiadiazoles as intermediates for useful transformations to other heterocycles have appeared. For example, the thiadiazole intermediate 36 was prepared from the hydrazone 35 and converted to benzofuran upon treatment with base. Similarly, the thiadiazole acid chloride 38 was converted to the hydrazine 39 which, upon base treatment, provided the pyrazolone, which can be sequentially alkylated in situ to provide the product 40. ... 

In some cases, a transition between J- and H-aggregates has also been observed. Mori et al. (1996) showed that astaxanthin H-aggregates transform into J-aggregates in a few hours. These authors studied the transformation in the 2°C-32°C temperature range and concluded that assemblies corresponding to H- and J-aggregates are separated by an energy barrier that allows the H to J... 

Tamura, T., Thibert, C., Royer, C. et al. 2000. Germline transformation of the silkworm Bombyx mori L. using apiggyBac transposon-derived vector. Nat. Biotechnol., 18(1) 81—84. 

The synthesis of the benzoimidazo[l,2- ][l,2,3]thiadiazole 61 can be explained using the same mechanistic model to that used for the Hurd-Mori reaction. The amino benzimidazole 58 when treated with thionyl chloride at reflux affords the benzoimidazo[l,2-r ][l,2,3]thiadiazole 61. If, however, the reactant 58 is treated with thionyl chloride at room temperature, the chloromethyl derivative 59 is formed. This derivative was then transformed into product 61 on reflux with thionyl chloride. The proposed mechanism for the formation of product 61 is for the initial formation of the sulfoxide 60, which then undergoes a Pummerer-like rearrangement, followed by loss of SO2 and HC1 to give the c-fused 1,2,3-thiadiazole 61 (Scheme 7) <2003TL6635>. 

An unexpected ring contraction reaction has been reported. The attempted hydrolysis of 3-methoxycarbonyl-177-thieno[2,3-< ][l,3,4]thiadiazine 4,4-dioxide 77 under acidic conditions gave the ring-contracted thieno[2,3-<7][l,2,3]thia-diazole 78 instead of the expected carboxylic acid (Equation 24). A similar mechanism to the Hurd-Mori reaction has been proposed for this transformation <2000JHC191>. 

In contrast to Mori s synthesis, Pawar and Chattapadhyay used enzymatically controlled enantiomeric separation as the final step [300]. Butanone H was converted into 3-methylpent-l-en-3-ol I. Reaction with trimethyl orthoacetate and subsequent Claisen-orthoester rearrangement yielded ethyl (E)-5-methyl-hept-4-enoate K. Transformation of K into the aldehyde L, followed by reaction with ethylmagnesium bromide furnished racemic ( )-7-methylnon-6-ene-3-ol M. Its enzyme-catalysed enantioselective transesterification using vinylacetate and lipase from Penicillium or Pseudomonas directly afforded 157, while its enantiomer was obtained from the separated alcohol by standard acetylation. 

The transformations of SbClj caused by a one-electron transfer from an aromatic compound have been described earlier. If the pure Lewis acid SbClj is used, its reactivity is very difficult to control, and single-electron oxidation as well as chlorination of various aromatic donors can occur readily (Mori et al. 1998). Meanwhile, in the case of EtjO SbClg", the slow release of the active monomer SbClj occurs. In the case of SbClj as such, the 2SbCl5 — C Sb—CI2—SbCl4 dimerization occurs (Cotton and Wilkinson 1988, p. 395). The dimeric form may lead to the following electrophilic chlorination ... 

Mori has independently developed a procedure for the cyclization/stannylsilylation of enynes similar to that developed by Lautens. As an example of Mori s procedure, reaction of dimethyl allylpropargylmalonate with trimethylsilyltributylstannane catalyzed by Pearlman s catalyst [Pd(OH)2/C] in THF at room temperature for 20 h formed cyclopentane 94 [X = C(C02Me)2] in 90% yield (Equation (61)). The transformation was compatible with a number of functional groups, tolerated limited substitution of the G=C bond, and was applicable to the synthesis of nitrogen heterocycles. In a notable example, reaction of the benzhydryl-protected allylpropargylamine 95 with MesSiSnBus catalyzed by Pd(OH)2/C formed the bis(functionalized) octahydroindole 96 in 66% yield as a single diastereomer (Equation (62)). 

The same model also can be obtained using the continued fraction representation.4 Following Mori,5 the Laplace transform of the velocity... 

F(q, t) is obtained from its Laplace transform form F(q,z)- By using the following well-known Mori continued-fraction expansion and truncating at second order, the viscoelastic expression for F(q, z) can be written as [16, 21, 22]... 

This cyclization is a reaction developed by Mori, who carried out a series of investigations with tin reagent 33. Fluoride is a much more reactive anion for initiation than any of the other halides, although it often leads to decomposition of the starting materials. In the case of vinylic or aryl halogen compounds the iodides are easier to transform than the bromides, and chlorides are unrcactive. The carbonyl group can be derived from either an aldehyde or a ketone, and even esters are sufficiently electrophilic.22... 

Mori Y, Ishida W, Bhattacharyya S, Li Y, Platanias LC, Varga J. Selective inhibition of activin receptor-like kinase 5 signaling blocks profibrotic transforming growth factor beta responses in skin fibroblasts. Arthritis and Rheumatism 2004, 50, 4008 1021. 

C-H activation pathway cannot be ruled out for this transformation, however. They subsequently observed C-H insertion of a cis substituent by means of isotope studies [32], The cycloheptene product was observed as the major product when cis- or tri-substituted enyne and acetylenic ester termini were present. Ruthenium hydride catalysts reported by Mori and Dixneuf can also initiate the cycloisomerization of 1,5- and 1,6-enynes and dienes [33, 34], The vinylruthenium hydride can be obtained from RuClH(CO)(PPh3)3 or in the presence of acetic acid or ethanol. 

Moriguchi Y, Matsubara H, Mori Y, Murasawa S, Masaki H, Maruyama K, Tsutsumi Y, Shibasaki Y, Tanaka Y, Nakajima T, Oda K, Iwasaka T. 1999. Angiotensin Il-induced transactivation of epidermal growth factor receptor regulates fibronectin and transforming growth factor-beta synthesis via transcriptional and posttranscriptional mechanisms. Circ Res 84 1073-1084. 

Mori started with the early introduction of the chiral centre [298] in using (3-oxidation of pentanoic acid A by the yeast, Candida rugosa, IFO 0750 [299]. The obtained (R)-3-hydroxypentanoic acid B was transformed into C in a few conventional steps. The second building block was prepared from methyl 2-pentynoate D conjugate addition of lithium dimethyl cuprate yielded E, which was further converted into the frans-configured vinyl bromide F. Hydro-boration of C yielded G which upon Suzuki s palladium catalysed cross-coupling with F furnished 157 after treatment of the reaction product with hydrochloric acid followed by chromatographic purification. The synthesis of ent-157 used (S)-3-hydroxypentanoic acid. 

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