Internal couplings

Other applications of similar couplings include the synthesis of tricyclic indole-2-carboxylic acids as N-methyl-D-aspartate (NMDA)-glycine antagonists [97] and 10-deoxyartemisinins against malaria [98]. 

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MetaUic ions are precipitated as their hydroxides from aqueous caustic solutions. The reactions of importance in chlor—alkali operations are removal of magnesium as Mg(OH)2 during primary purification and of other impurities for pollution control. Organic acids react with NaOH to form soluble salts. Saponification of esters to form the organic acid salt and an alcohol and internal coupling reactions involve NaOH, as exemplified by reaction with triglycerides to form soap and glycerol,... 

The structure of heart myocytes is different from that of skeletal muscle fibers. Heart myocytes are approximately 50 to 100 p,m long and 10 to 20 p,m in diameter. The t-tubules found in heart tissue have a fivefold larger diameter than those of skeletal muscle. The number of t-tubules found in cardiac muscle differs from species to species. Terminal cisternae of mammalian cardiac muscle can associate with other cellular elements to form dyads as well as triads. The association of terminal cisternae with the sarcolemma membrane in a dyad structure is called a peripheral coupling. The terminal cisternae may also form dyad structures with t-tubules that are called internal couplings (Figure 17.31). As with skeletal muscle, foot structures form the connection between the terminal cisternae and t-tubule membranes. 

Signal internalization (coupled with endocytosis, eg, the LDL receptor)... 

An interesting example of an internal coupling reaction is provided by the diazotisation of o-diaminobenzene (36) ... 

Vinylstannane compounds containing a remote vinyl halide moiety undergo a stereospecific internal coupling reaction, catalysed by cuprous iodide, leading to conjugated dienes, as illustated, for example, in reaction 66. ... 

In summary, we have examined several models both with and without internal coupling, in order to get some insight into the possible form that might be taken by the decoupling of initial correlations. We have shown that decoupling occurs in some form for all of these models. Since the possible forms of decomposition that we have studied (i.e., the cumulant... 

The final step in the generalization of the direct Cl method was the realization that the full list of coupling coefficients Afj rs can be generated from a small set of prototype coupling coefficients B ra, initially termed internal coupling coefficients. 

In contrast to 41a-c, the prerequisites for an internal coupling are lacking in 41d-f because of the absence of additional CN donors. 

The enzymatic reactor consisted of a 500 mL-continuous tank reactor BIOSTAT Q (Braun-Biotech International) coupled to the ultrafiltration membrane. The additional volume of the ultrafiltration unit and piping was around 150 mL. Three solutions were added to the reactor by means of three variable speed peristaltic pumps, containing (a) Orange II, Mn2+ and oxalic acid (b) H2O2 and (c) MnP. Another peristaltic pump was used in order to feed the effluent into the ultrafiltration unit (Fig. 10.3). The recycling feed flow ratio was maintained at 12 1, as this flow rate allowed an adequate homogeneity of the enzymatic mixture but prevented the polarization or fouling of the membrane. 

Although attempts to make pyrrole diazonium salts couple inter-molecularly have been unsuccessful, 3-diazo-2,4,5-triphenylpyrrole (21) on prolonged heating in dilute sulfuric acid undergoes internal coupling (21- -41).21 That coupling occurred with the phenyl group in the 4-position rather than the 2-position is shown by the formation of the diketone (42) on oxidation with nitric acid. 

Pandey, G. Rani, K.S. Eakshimaiah, G. Tetrahedron Lett. 1992, 33, 5107. See Gelas-Mialhe, Y Gramain, J.-C. Eouvet, A. Remuson, R. Tetrahedron Lett. 1992, 33, 73 for an internal coupling reaction of an allyl silane and an a-hydoxy lactam. 

C-nitrosation or internal coupling.1 13 On treatment with nitrous acid 1-aminoquinolizinum salts undergo rearrangement to triazolo[l,5 ]pyridines (Section IV,F). The secondary 2-arylaminoquinolizinium salts can be de-protonated to give 2-aryliminoquinolizines such as 219.172 173... 

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