Synthesis of tertiary amines by direct Brønsted acid catalyzed reductive amination

Abstract

<p>Triflic acid efficiently promotes the reductive amination reactions of carbonyl compounds on a broad range of substrates.</p>

HFIP in Organic Synthesis

“…Tertiary amines were accessed in a reductive amination reaction of aldehydes and formamides in HFIP containing catalytic TfOH (Scheme ). The reaction was developed using DMF as both solvent and amine source, leading to the designation of TfOH as the optimal Brønsted acid. To avoid having to use solvent-quantities of formamide substrates, the authors screened solvents capable of promoting the transformation.…”

Selective synthesis of 3-formylbenzofuran and 3-acylbenzofuran using a chalcone rearrangement strategy

“…The mechanism of 3-formylbenzofuran 5 formation is via a diprotonated intermediate A (path ii), 12 which is stabilized with (CF 3 ) 2 CHOH. 13,14 Subsequent THF ring opening of intermediate A gives B , and the ring-closure at the ketone moiety then lead to 5 after aromatization and hydrolysis. According to Zanatta, 15 another possible pathway for the formation of 5 is isomerization from 4 .…”

A Journey from June 2018 to October 2021 with N,N-Dimethylformamide and N,N-Dimethylacetamide as Reactants

“…The reaction of L-proline with DMF would precede the nucleophilic addition of the amine, while Fe III would form a DMF complex that reacts with the amine. Triflic acid catalyzed the formylation of tetrahydroisoquinoline with DMF (Scheme 32d) [93]. In fact, formylations with DMF arose at 150 • C even in the absence of an additive, in fair to high yields from various aliphatic amines and a low yield from p-methoxyaniline (Scheme 33a) [94].…”

“…The Leuckart-type reaction between wet DMF and aldehydes or ketones arose at 140-160 • C under catalysis with various Lewis [152][153][154] or Brønsted [93] acids (Scheme 49). The use of DCON(CD 3 ) 2 led to the d 7 -reductive amination product [93,152]. The acidic conditions cause the formation of HCOOH and HNMe 2 from HCONMe 2 and H 2 O.…”