Sequential treatment with trimethylsilyl iodide then methanol can also be used for Boc deprotection,[7][8] especially where other deprotection methods are too harsh for the substrate.[9] The mechanism involves silylation of the carbonyl oxygen and elimination of tert-butyl iodide (1), methanolysis of the silyl ester to the carbamic acid (2) and finally decarboxylation to the amine (3).[10]
Heating a mixture of the amine to be protected and di-tert-butyl dicarbonate in tetrahydrofuran (THF) at 40°C[12]
Add the amine to sodium hydroxide and di-tert-butyl dicarbonate in water and THF at 0°C then warm to ambient temperature.[13]
Heating a mixture of the amine to be protected and di-tert-butyl dicarbonate in a biphasic mixture of chloroform and aqueous sodium bicarbonate at reflux for 90 minutes.[14]
BOC-protected amines are prepared using the reagent di-tert-butyl-iminodicarboxylate. Upon deprotonation, this reagent affords a doubly BOC-protected source of NH− 2, which can be N-alkylated. The approach is complementary to the Gabriel synthesis of amines.
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Lundt, Behrend F.; Johansen, Nils L.; Vølund, Aage; Markussen, Jan (1978). "Removal of t-Butyl and t-Butoxycarbonyl Protecting Groups with Trifluoroacetic acid". Int. J. Pept. Protein Res.12 (5): 258–268. doi:10.1111/j.1399-3011.1978.tb02896.x. PMID744685.
Zhijian Liu; Nobuyoshi Yasuda; Michael Simeone; Robert A. Reamer (2014). "N-Boc Deprotection and Isolation Method for Water-Soluble Zwitterionic Compounds". J. Org. Chem.79 (23): 11792–11796. doi:10.1021/jo502319z. PMID25376704.
Chankeshwara, Sunay V.; Chakraborti, Asit K. (2006). "Catalyst-Free Chemoselective N-tert-Butyloxycarbonylation of Amines in Water". Org. Lett.8 (15): 3259–3262. doi:10.1021/ol0611191. PMID16836380.
Englund, Ethan A.; Gopi, Hosahudya N.; Appella, Daniel H. (2004). "An Efficient Synthesis of a Probe for Protein Function: 2,3-Diaminopropionic Acid with Orthogonal Protecting Groups". Org. Lett.6 (2): 213–215. doi:10.1021/ol0361599. PMID14723531.
Stahl, Glenn L.; Walter, Roderich; Smith, Clark W. (1978). "General Procedure for the Synthesis of Mono-N-Acylated 1,6-Diaminohexanes". J. Org. Chem.43 (11): 2285–2286. doi:10.1021/jo00405a045.
Prashad, Mahavir; Har, Denis; Hu, Bin; Kim, Hong-Yong; Girgis, Michael J.; Chaudhary, Apurva; Repič, Oljan; Blacklock, Thomas J.; Marterer, Wolfgang (2004). "Process Development of a Large-Scale Synthesis of TKA731: A Tachykinin Receptor Antagonist". Org. Process Res. Dev.8 (3): 330–340. doi:10.1021/op0341824.