Reactions, coupled secondary

Nitriles and oximes are considered together because of common features. Both functions are reduced to primary amines, both undergo coupling reactions to secondary amines, and both are subject to reductive hydrolysis. These similarities arise from a common intermediate, an imine. The imine is... 

Glycosyl phosphorimidate donors were obtained by the synthetic sequence outlined in Scheme 6.14. These glycosyl donors were coupled with primary acceptor glycosides in moderate to excellent yields, and depending on the reaction conditions (Scheme 6.15) either a- or p-selcctivitics were observed.51 p-ScIcctivc mannosylations and glycosylation on reaction of secondary hydroxyl containing acceptors did not prove feasible. 

Proteins can be detected in tissue sections or cell cultures using similar immune detection systems. Use of an antibody to detect specific proteins in tissues is called immunohistochemistry, whereas detection of proteins in cell suspensions is called immunocyto-chemistry. Tissues can be prepared by fixation and embedding in paraffin wax, or by rapid freezing in a compound that inhibits ice formation in the tissue, so as to preserve cell morphology. Some antibodies do not work well with paraffin-embedded tissues, probably because the antibody cannot access the antigen properly (133). The most common labeling system used for detection of the bound antibody is an enzyme-coupled secondary antibody that produces a color reaction... 

Furthermore, bromothioethenes were reported as fairly useful electrophiles for the coupling reaction with secondary Grignard reagents (Table 5.1, entries 18 and 19) [13]. These transformations occur highly stereo- and chemoselectively at the vinyl bromide moiety whereas the thiophene functionality remains conserved under the described reaction conditions. 

In 1996, Wolfe and Buchwald reported that the (o-tolljP/Pd catalyst system effectively couples secondary amines with aryl iodides, Eq. (37) [67]. This protocol allowed for the successful reaction of both cychc and acyclic secondary amines the use of dioxane as solvent was key to the success of these reactions. Similarly, Zhao and co-workers reported the couphng of aryl iodides and piperazines mediated by the (o-tolljP/Pd catalyst [25b]. 

The coupling of aryl bromides with primary aHphatic amines often suffered from the formation of reduced arene by-products similar to the reactions with secondary amines. For example, the use of ( )-BINAP as a Hgand greatly improved the yield in the coupling of 5-bromo-raefa-xylene and -hexylamine, Eq. (64) [27]. 

The technique described above is not useful for removing colored peroxidase reaction products (e.g., diaminobenzidine oxidation products) from blots. Thus, we avoid the use of peroxidase-coupled secondary antibodies. On the other hand, recently described peroxidase-based luninescence assays (16) do not deposit a chemical reaction product on the blot and should be compatible with this erasure method. 

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