A novel thiourea type organocatalyst possessing a single NH functionality

Abstract

A novel thiourea organocatalyst was rationally designed by altering a typical H-bonding pattern of thiourea derivatives and utilising the potential of the 3,5-bis(trifluoromethyl)phenyl motif to participate in the H-bond formation. This unique catalyst afforded the products of the α-amination and Michael reaction in excellent yields and with a high level of stereoselectivity. Although additional studies are necessary to establish the full potential of the catalyst and to broaden its application further, the presented results may indicate alternative routes for further exploration of the thiourea class of organocatalysts.

An efficient organopromotor L‐arginine facilitated synthesis of thiazolo[3,2‐a]pyrimidine derivatives in EtOH:H2O solvent

“…The large volume of reports shows that L-arginine is one of the utmost metabolically versatile amino acids and is involved in many biological processes [13,14]. L-arginine is an effectively accessible, miniature bioorganic molecules that can be quickly degraded in the earth without producing considerable effluent [15][16][17][18][19]. Due to the presence of positively charged guanidinium group on the side chain, L-arginine is the most basic amino acid.…”

Enantioselective Synthesis of β-Hydrazino Alcohols Using Alcohols and N-Boc-Hydrazine as Substrates

“…Construction of heteroatom-connected stereogenic carbon is frequently a much sought-after goal and challenge in organic chemistry and the past decade has witnessed various strategies for asymmetric C–N bond formation, wherein α-amination of aldehydes holds an important position. Since in situ generated α-hydrazino aldehydes are readily converted into β-hydrazino alcohols, oxazolidinones, β-amino alcohols, and α-amino acid derivatives, their enantioselective synthesis has been attracting tremendous attention and interest . The pioneering study, made independently by the groups of List and Jørgensen in 2002, was the l -proline-catalyzed direct asymmetric α-hydrazination of aldehydes using azodicarboxylates as the electrophilic aminating agent (Scheme a). , From then on, the majority of chiral amine catalysts have been exploited to construct such an amination pattern .…”

“…Since in situ generated α-hydrazino aldehydes are readily converted into β-hydrazino alcohols, oxazolidinones, β-amino alcohols, and α-amino acid derivatives, their enantioselective synthesis has been attracting tremendous attention and interest . The pioneering study, made independently by the groups of List and Jørgensen in 2002, was the l -proline-catalyzed direct asymmetric α-hydrazination of aldehydes using azodicarboxylates as the electrophilic aminating agent (Scheme a). , From then on, the majority of chiral amine catalysts have been exploited to construct such an amination pattern . For example, Meggers and his co-workers developed a bifunctional chiral-at-metal Ir III catalyst (Scheme b) and very recently the group of Leigh reported a mechanically driven point-chiral rotaxane catalyst that provided products in low ee (Scheme c) .…”