Molecular Iodine-Catalyzed Facile Procedure for N-Boc Protection of Amines

Abstract

An efficient and practical protocol for the protection of various structurally and electronically divergent aryl and aliphatic amines using (Boc)2O in the presence of a catalytic amount of molecular iodine (10 mol %) under solvent-free conditions at ambient temperature is presented.

Synthesis of Phidianidine B, a highly cytotoxic 1,2,4-oxadiazole marine metabolite

“…13 The subsequent introduction of the tert-butyloxycarbonyl (BOC) group on the amino function of 4 was achieved by using di-tert-butyl dicarbonate and 10 mol% of I2 in a solvent free reaction, obtaining the protected derivative 5. 14 The following addition of a N,Ndimethyl formamide solution of cyanamide and sodium amide to compound 5 gave the corresponding 1-cyanamino derivative 6. This latter compound was treated with hydroxylamine hydrochloride and sodium methoxide in anhydrous methanol leading to the key intermediate 2.…”

Succinimide sulfonic acid (SuSA): an efficient and recyclable catalyst for the chemoselective N-Boc protection of amines

“…Di-tert-butyl dicarbonate [(Boc) 2 O] as a stable and commercially available reagent is widely used for this purpose [5,6]. Many methods have been reported to improve the rate of the N-Boc protection with (Boc) 2 O using basic or acidic catalysts [7][8][9][10][11][12][13][14][15][16][17][18][19][20]. Although these procedures provide an improvement, most of them suffer from disadvantages such as long reaction times, tedious work-up, the use of corrosive or moisture-sensitive reagents, the formation of side-products during base-catalyzed reactions, difficulty in the preparation of the reagent, and using an excess of reagent in the case of Lewis acidcatalyzed reactions.…”

Saccharin sulfonic acid catalyzed N-Boc protection of amines and formation of tert-butyl ethers from alcohols

“…Many methods have been reported which were meant to improve the rate of the N-Boc protection with *Corresponding author. E-mail: shirini@guilan.ac.ir (Boc) 2 O using basic or acidic catalysts [7][8][9][10][11][12][13][14][15][16][17][18][19][20]. Although these represent some improvement, most of them suffer from disadvantages such as long reaction times, tedious work-up, the use of corrosive or moisture sensitive reagents, formation of side-products during base-catalyzed reactions, difficulty in the preparation of the reagent, and using excess of reagent in the case of Lewis acid catalyzed reactions.…”