A practical, catalytic and selective deprotection of a Boc group in N,N′-diprotected amines using iron(iii)-catalysis

Abstract

A selective, catalytic and practical method for removing a Boc group from several N,N′-diprotected amino acids and amine derivatives using iron(iii) salts as sustainable catalysts is described.

FeCl3‐Mediated Boc Deprotection: Mild Facile Boc‐Chemistry in Solution and on Resin

“…GCMS based experiments were also not recommended as removing the metal from the column could be challenging. However, we proposed a plausible mechanistic pathway for Boc‐cleavage (Scheme ) based on reported literature …”

“…Padron et al . disclosed the removal of the Boc group from dimethyl ester of N, N ‐Boc, Ts‐amino acid using Lewis acid, ferric chloride (FeCl 3 ) …”

Deprotection of N‐tert‐Butoxycarbonyl (Boc) Protected Functionalized Heteroarenes via Addition–Elimination with 3‐Methoxypropylamine

“…However, subsequent attempts to optimize this transformation towards reliable production and chromatographic isolation of 4 proved elusive. Further experimentation was attempted by employing standard Lewis acids including SiO 2 , CuI, and LiCl (entries 7–9) without success. AlCl 3 affected conversion of 3 to 4 , but with significant decomposition.…”

Enantiodivergent Synthesis of (+)‐ and (−)‐Pyrrolidine 197B: Synthesis of trans‐2,5‐Disubstituted Pyrrolidines by Intramolecular Hydroamination

“…The Wittig olefination of aldehyde 4 with unstabilized or stabilized ylides provided the desired unsaturated tosylamines 5 and 7 , respectively (Scheme ). Subsequent treatment of these tosylamino alkenes with FeCl 3 permitted us to remove the N ‐Boc group with concomitant IHR in a single reaction step with excellent reaction yields . In both cases, the enantiopure trans ‐5‐substituted proline derivatives were obtained regardless of the stereochemistry of the initial double bond (Scheme ).…”

“…Subsequentt reatment of these tosylaminoa lkenes with FeCl 3 permitted us to removet he N-Boc group with concomitantI HR in as ingle reactions tep with excellent reactiony ields. [25] In both cases, the enantiopure trans-5-substituted proline derivatives were obtained regardless of the stereochemistry of the initial double bond (Scheme 7). The access to these trans-5-substituted prolines could be achieved in af ew steps by meanso fN-detosylation and hydrolysis of the ester functionality.…”