Boc protecting groups

Step 2 The Boc protecting group is removed by treatment with hydrochloric acid m dilute acetic acid After the resin has been washed the C terminal ammo acid IS ready for coupling... 

Step 4 The Boc protecting group is removed as m step 2 If desired steps 3 and 4 may be repeated to introduce as many ammo acid residues as desired... 

Amino groups are often protected as their tert-butoxycarbonvl amide, or Boc, derivatives. The Boc protecting group is introduced by reaction of the amino acid with di-fert-butyl dicarbonate in a nucleophilic acyl substitution reaction and is removed by brief treatment with a strong organic acid such as trifluoro-acetic acid, CF3C02H. 

The use of diamine 27, bearing a fluorous-Boc protecting group, has been used with microwave irradiation in an Ugi/de-Boc/cyclization strategy for the synthesis of benzimidazoles 28 and quinoxalinones 29 [64]. Compared to the original procedures, which take 1-2 days, this approach avoids the use of... 

Recently the use of the boron trifluoride catalysed reaction in the synthesis of the oxazolylindole fragment 25 of the natural product diazonamide A has been reported.<96SL609> Thus the BF3-mediated reaction of the indolyl diazoketoester with acetonitrile gave oxazole 25 with simultaneous removal of the Boc-protecting group (Scheme... 

Then, we synthesized AB6 dendron 31 with six molecules of aminomethyl-pyrene as reporter units and the f-butyloxycarbonyl (Boc) protecting group as a trigger (Fig. 5.23). The dendron was designed to release its six tail units upon removal of the protecting group. 

Molecular structure of a self-immolative AB6 dendron with aminomethyl-pyrene reporter units and a Boc protecting group as a trigger. 

FIGURE 5.24 Release of aminomethyl-pyrene from dendron 31 upon removal of the Boc protecting group trigger (1 1 MeOH/DMSO mixture with 2% aqueous solution of Bu4NOH) ( ) Control reaction under similar conditions with dendron 31 with the Boc trigger intact (A)-... 

Selective hydrogenolysis of the benzyl ether group was performed in the presence of an N-Boc protecting group. In this case, 10 Pd/C (0.45 mol/mol) and HC02NH4 (6.5 mol/mol) was warmed at reflux in acetone for 30 minutes (Scheme 4.55).258... 

N-debenzylation was achieved with Pd black in AcOH-H20 (4 1) at 50 psi hydrogen for 2-3 days. Removing of O-benzyl, N-benzyl, and N-Boc protecting groups was also achieved under these circumstances (Scheme 4.89).337... 

Reaction of /cr/-butyl 1-hydrazinecarboxylates with triphosgene and ethyl 2-pyrrolidinecarboxylate, followed by removal of the BOC-protecting group with gaseous hydrogen chloride in anhydrous acetic acid, yielded hexahydro-pyrrolo[l,2-rf][l,2,4]triazin-l,4-dione 79 (Scheme 9) <2003SC1011>. 

Figure 2. Gel Permeation Chromatogram of the copolymer (a) before and (b) after removal of the t-BOC protecting groups...

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