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

Abstract

Succinimide sulfonic acid (SuSA) as a stable reagent is easily prepared by the reaction of succinimide with neat chlorosulfonic acid. This compound is able to catalyze the chemoselective conversion of amines to their corresponding N-Boc protected derivatives with (Boc) 2 O. All reactions were performed under mild conditions, giving the desired products in good to high yields.

Synthesis of 2 H- indazolo[2,1- b ]phthalazine-1,6,11(13 H )-triones using 1,4-disulfo-1,4-diazabicyclo[2.2.2]octane-1,4-diium dihydrogen sulfate {DABCO(HSO 3 ) 2 (HSO 4 ) 2 } as a new ionic liquid catalyst

“…In recent years preparation, characterization and use of N-sulfonic acids in organic reactions became an important part of our ongoing research program [18][19][20][21][22][23][24][25][26][27][28][29][30][31], in the continuation of these studies we were interested to investigate the preparation of [DABCO](SO 3 H) 2 (HSO4) 2 and its applicability in the promotion of the organic reactions.…”

[PVP‐SO3H] HSO4: An Efficient Polymeric Solid Acid Catalyst for the Formylation and N‐Boc Protection Reactions

“…), di‐ tert ‐butyl dicarbonate is the most popular one because of its commercial availability, stability and low cost . The N ‐Boc protection reaction was performed using various catalysts such as [(HMIm)BF 4 ], SaSA, Zn(ClO 4 ) 2 ⋅6H 2 O, (CF 3 ) 2 CHOH, HClO 4 /SiO 2 , succinimide sulfonic acid (SuSA), H 3 PW 12 O 40 and sulfamic acid …”

“…Although the above mentioned procedures provide an improvement in the protection of amines and alcohols, many of them suffer from some disadvantages such as harsh reaction conditions, need to long time for reaction, low yield of products, formation of an undesirable or toxic by‐product, need to a large amount of the catalyst for the performance of the reaction, applying toxic solvents and non‐recoverability of the catalyst . Thus, a simple method with an appropriate and high yield that employs an inexpensive catalyst will be valuable.…”

Succinimide-N-sulfonic acid as an efficient recyclable catalyst for the synthesis of some fused indolo pyrano pyrimidinone derivatives

“…Recently, succinimide-N-sulfonic acid (SuSA) has been used as a catalyst for chemoselective trimethylsilylation of alcohols and phenols with hexamethyldisilazane (HMDS) [21], chemoselective conversion of amines to their corresponding N-Boc protected derivatives with (Boc) 2 O [22] and also for the acetylation reactions in the absence of a solvent [23]. As part of continuing effort in our laboratory towards the development of environmentally friendly procedures for the synthesis of biologically active heterocyclic molecules [24][25][26], we now describe the synthesis of 5,6-dihydro-2-(2-oxo-2H-chromen-3-yl)-5-phenyl-indolo[2',3':5,6]-pyrano [2,3-d]pyrimidin-4(3H)-one derivatives from the reaction of 2-amino-4,5-dihydro-4-phenylpyrano [3,2-b]indole-3-carbonitriles and coumarine-3-carboxylic acid using SuSA as an efficient reusable catalyst under solvent-free conditions.…”