Morita mechanism

Ishii Morita, H., Agbaria, R., Mullan, C.A., Hirano, H., Koeplin, D.A., Ram, Z., Oldfield, E.H., lohns, D.G., and Blaese, R.M., Mechanism of bystander effect killing in the herpes simplex thymidine kinase gene therapy model of cancer treatment, Gene Therapy, 1997, 4, 244—251. 

Yamawaki, Y., Morita, M. and Sakata, I. (1990). Mechanical and dielectric properties of cyanoethylated wood. Journal of Applied Polymer Science, 40(9-10), 1757-1769. 

Yazaki K, Sugiyama A, Morita M, Shitan N. 2008. Secondary transport as an efficient membrane transport mechanism for plant secondary metabolites. Phytochem Rev 7 513-524. 

The mechanism of Morita-Baylis-Hillman (MBH) alkylation has been investigated.22 An MBH intermediate exhibiting unprecedented trans geometry of the phos-phonium salt and acyl group has been isolated for the first time. 

A series of A - / - n i trobe nzenesul fony 1 imincs have been reported to undergo asymmetric aza-Morita-Baylis-Hillman reactions with methyl acrylate mediated by DABCO in the presence of chiral thiourea organocatalysts with unprecedented levels of enantioselectivity (87-99% ee), albeit only in modest yields (25 19%). Isolation of a DABCO-acrylate-imine adduct as a key intermediate, kinetic investigation, and isotopic labelling, have been employed to determine the mechanism.177... 

In a different study, based on the reaction rate data collected in aprotic solvents, the Morita-Baylis-Hillman reaction has been found to be second order in aldehyde and first order in DABCO and acrylate. On the basis of these data, a new mechanism has been proposed, involving a hemiacetal intermediate (110). The proposed mechanism is further supported by two different kinetic isotope effect experiments.145... 

According to another NMR study, the mechanism of bifunctional activation in the asymmetric aza-Morita-Baylis-Hillman reaction (Scheme 7) involves rate-limiting proton transfer (116) in the absence of added protic species155 (in consonance with the report summarized in Scheme 5144), but exhibits no autocatalysis. Addition of Brpnsted acids led to substantial rate enhancements through acceleration of the elimination step. Furthermore, it was found that phosphine catalysts, either alone or in combination with protic additives, can cause racemization of the reaction product by proton exchange at the stereogenic centre. This behaviour indicates that the spatial arrangement of a bifunctional chiral catalyst for the asymmetric aza-Morita-Baylis-Hillman reaction is crucial not only for the stereodifferentiation within the catalytic cycle but also for the prevention of subsequent racemization.155... 

A NHC-catalyzed aza-Morita-Baylis-Hillman reaction (aza-MBH) following a standard nucleophile-mediated MBH mechanism has been disclosed very recently (He et al. 2007). Although combined with a preceding equilibrium for the reversible formation of imine-carbene adducts this reaction has similarities with phosphines and their organo-catalytic reactivity (Methot and Roush 2004). 

As shown in Equation (17), 2-trimethylsilyloxyfuran also participated in a triphenylphosphine-catalyzed substitution reaction with Morita-Baylis-Hillman acetates to provide interesting 7-butenolides regio- and diastereoselec-tively <2004AGE6689>. However, the reaction mechanism (vinylogous Michael vs. Diels-Alder) has not been distinguished. 

Morita etal. (2001) also examine the mechanics of nickel short-circuiting in Li/Na cells at ambient pressure. There is a process of linking local precipitation sites into chains, which extend into short circuits. 

Morita T, Maki K, Aiba H. RNase E-based ribonucleoprotein complexes mechanical basis of mRNA destabihzation mediated by bacterial noncoding RNAs. Genes Dev. 2005 19(18) 2176-2186. 

Tsuchiya Y, Morita T, Kim M, Iemura S, Natsume T, Yamamoto M, Kobayashi A (2011) Dual regulation of the transcriptional activity of Nrfl by beta-TrCP- and Hrdl-dependent degradation mechanisms. Mol Cell Biol 31(22) 4500-4512. doi 10.1128/ MCB.05663-11... 

Morita, et. al. (38) suggested that the polymerization mechanism may be different at high and low frequencies. They believe that polymerization through radical intermediates is the predominant mechanism at discharge frequencies higher than a few MHz, but that... 

Propose a mechanism for the following formation of the aza Morita Baylis Hillman reaction product that is obtained from an a hydroxypropargylsilanc (1) and the N tert butanesulfinyl imine. Provide the structure of intermediate A obtained upon slow addition of n BuLi to ( ) 1. 

Morita, A., Kato, S., Theoretical Study on the Intersystem Crossing Mechanism of a Diradical in Norrish Type II Reactions in Solution, J. Phys. Chem. 1993, 97, 3298 3313. 

Morita, T, et ah [Activation mechanism of human prothrombin by staphylocoagulase]. Rin-sho Byori (Jpn J Clin Pathol) 1982, Suppl, 127-136. 

Murakami, K., Kondo, T., Yang, G., Chen, S.F., Morita-Fujimura, Y., and Chan, P.H., Cold injury in mice A model to study mechanisms of brain edema and neuronal apoptosis, Prog. NeurobioL, 57(3), 289, 1999. 

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