Enantioselective Synthesis of Hydrothiazole Derivatives via an Isocyanide-Based Multicomponent Reaction

Abstract

Catalytic asymmetric synthesis of hydrothiazole derivatives was developed via a well-organized formal [2 + 1 + 2] cycloaddition reaction triggered by asymmetric addition of isocyanide to alkylidene malonate. Various chiral hydrothiazole derivatives were readily provided in good yield with high enantioselectivity (up to 98% yield, 98.5:1.5 er) utilizing a chiral Mg­(OTf)2/N,N′-dioxide complex as the catalyst under mild conditions. Based on the experimental studies and the structure of the catalyst, a possible catalytic cycle was proposed to elucidate the reaction process and activation mode.

Catalytic Enantioselective Isocyanide‐Based Reactions: Beyond Passerini and Ugi Multicomponent Reactions

“…; Scheme 28). [79] This process could also be applied to both benzoxazole and phenanthridine, giving the corresponding products 124 c and 124 d in poor to moderate yields and good to excellent enantioselectivities. However, the less reactive 1‐benzyl‐1 H ‐benzo[ d ]‐imidazole and differently substituted pyridines were not suitable reaction partners.…”

Synthesis of Sulfamate‐Fused 2‐Aminopyrroles via an Isocyanide‐Based Three Component [1+2+2] Annulation

“…[9] Despite the impressive progress achieved, further exploration of other types of reactions to enrich the scope of sulfamate-fused pyrroles is still importantf or organic chemistry.E specially,t he efficient preparation of sulfamatefused pyrroles under metal-free mild conditions will be particularly meaningful.Multicomponent reactions (MCRs) [10] are the mostp owerful and significant synthetic methods to construct fused heterocyclic scaffolds with high efficiency and atom economy.A mong them, isocyanide based multicomponent reactions (IMCRs) have attracted considerable attentions over the past decades. [11] Various synthetic routes to pyrroles under basicconditions, [12] as well as transition metal catalyzed IMCRs [13] from isocyanides, have been explored.I MCRs containing zwitterions derived from isocyanides and acetylene compounds have been provent ob ep articularly powerful strategies fort he construction of such complex frameworks. [14] However,t ot he best of our knowledge, synthesis of densely functionalized fused pyrroles by IMCRs under neutrala nd metal-free conditions has not been uncovered.…”

Efficient synthesis of novel 2‐(2‐chloroquinolin‐3‐yl)imidazo[1,2‐a]pyridin‐3‐amine derivatives

“…[9] Due to the high activity of this compounds, isocyanides are applied in several multicomponent reactions. [10][11][12] Therefore, this class of compounds has been used in several organic reactions for the synthesis of various useful compounds, including lactams, [13] hydrothiazoles, [14] limidazo [1,2-a]pyridine, [15] imidazothiadiazolamine, [16] macrocyclic compounds, [17] and polymeric materials. [18] Regarding the advantages of isocyanide containing multicomponent reactions, we hereby report an efficient method based on these reactions for the synthesis of 2-(2-chloroquinolin-3-yl)imidazo[1,2-a]pyridin-3-amine derivatives.…”

“…[ 9 ] Due to the high activity of this compounds, isocyanides are applied in several multicomponent reactions. [ 10–12 ] Therefore, this class of compounds has been used in several organic reactions for the synthesis of various useful compounds, including lactams, [ 13 ] hydrothiazoles, [ 14 ] limidazo[1,2‐a]pyridine, [ 15 ] imidazothiadiazolamine, [ 16 ] macrocyclic compounds, [ 17 ] and polymeric materials. [ 18 ]…”