Preparation of mono-substituted malonic acid half oxyesters (SMAHOs)

• Tania Xavier,
• Sylvie Condon,
• Christophe Pichon,
• Erwan Le Gall and
• Marc Presset

Beilstein J. Org. Chem. 2021, 17, 2085–2094, doi:10.3762/bjoc.17.135

• widespread applications being aldol or Mannich-type addition reactions with carbonyl compounds and imines, respectively [4], and Galat olefination reactions of aldehydes [5][6][7]. Nevertheless, these developments have been mostly described with unsubstituted MAHOs, and the use of mono-substituted MAHOs

A speedy route to sterically encumbered, benzene-fused derivatives of privileged, naturally occurring hexahydropyrrolo[1,2-b]isoquinoline

• Olga Bakulina,
• Alexander Ivanov,
• Vitalii Suslonov,
• Dmitry Dar’in and
• Mikhail Krasavin

Beilstein J. Org. Chem. 2017, 13, 1413–1424, doi:10.3762/bjoc.13.138

• ) N-acylation of the imine component followed by intramolecular Mannich reaction or (b) Mannich-type addition of the HPA enolate to a protonated imine component followed by intramolecular aminolysis of the cyclic anhydride moiety in Mannich adduct 13 (Scheme 3) [1]. Investigation of the CCR leading to

Multicomponent reactions: A simple and efficient route to heterocyclic phosphonates

• Mohammad Haji

Beilstein J. Org. Chem. 2016, 12, 1269–1301, doi:10.3762/bjoc.12.121

• under optimized conditions were 53–89%. This process involved a Mannich-type addition of a silver-activated α-isocyanophosphonate anion 208 to an iminium salt 207, resulting from reaction of amine 204 and ketone 205, to give intermediate 209 which cyclizes to afford (2-imidazolin-4-yl)phosphonates 210

One-pot stereoselective synthesis of α,β-differentiated diamino esters via the sequence of aminochlorination, aziridination and intermolecular S_N2 reaction

• Yiwen Xiong,
• Ping Qian,
• Chenhui Cao,
• Haibo Mei,
• Jianlin Han,
• Guigen Li and
• Yi Pan

Beilstein J. Org. Chem. 2014, 10, 1802–1807, doi:10.3762/bjoc.10.189

• corresponding β,γ-amino alcohols and vicinal diamines. α,β-Diamino acid derivatives have been served as organocatalysts, chiral ligands, chiral auxiliaries for asymmertric synthesis [10][11][12], as well as synthetic fragments for peptides and natural products [13]. Mannich-type addition reactions of α-amino

Silver and gold-catalyzed multicomponent reactions

• Giorgio Abbiati and
• Elisabetta Rossi

Beilstein J. Org. Chem. 2014, 10, 481–513, doi:10.3762/bjoc.10.46

• (Scheme 33) [90][91]. The reaction occurs via a Mannich-type addition of the deprotonated isocyanide intermediate 64 to an in situ generated iminium salt, a subsequent intramolecular cyclization and proton shift results in dihydroimidazole 65 showing predominantly cis-arrangment around the C4–C5 bond

Asymmetric synthesis of γ-chloro-α,β-diamino- and β,γ-aziridino-α-aminoacylpyrrolidines and -piperidines via stereoselective Mannich-type additions of N-(diphenylmethylene)glycinamides across α-chloro-N-sulfinylimines

• Gert Callebaut,
• Sven Mangelinckx,
• Pieter Van der Veken,
• Karl W. Törnroos,
• Koen Augustyns and
• Norbert De Kimpe

Beilstein J. Org. Chem. 2012, 8, 2124–2131, doi:10.3762/bjoc.8.239

• ,2R,3R)-γ-chloro-α,β-diaminocarboxyl esters obtained via Mannich-type addition of analogous N-(diphenylmethylene)glycine esters across a chiral α-chloro-N-p-toluenesulfinylaldimine. Selective deprotection under different acidic reaction conditions and ring closure of the γ-chloro-α,β

• ; Mannich-type addition; N-sulfinylimines; stereoselectivity; Introduction In recent years, non-proteinogenic diaminocarboxylic acids have gained a lot of attention among organic chemists and biochemists [1][2][3]. This is due to the fact that these diaminocarboxylic acids are present as key structural

• potency of analogous α,β-diaminocarboxylamides exists [15]. The synthesis of chiral α,β-diaminocarboxylic acid derivatives by asymmetric Mannich-type addition of enolates across activated imines, e.g., N-sulfinylimines [16][17][18][19][20], is one of the most common and versatile methods in organic

Facile synthesis of functionalized tetrahydroquinolines via domino Povarov reactions of arylamines, methyl propiolate and aromatic aldehydes

• Jing Sun,
• Hong Gao,
• Qun Wu and
• Chao-Guo Yan

Beilstein J. Org. Chem. 2012, 8, 1839–1843, doi:10.3762/bjoc.8.211

• published domino Povarov reaction [45][46][47][48][49]. At first, arylamine adds to methyl propiolate to form the β-enamino ester A. Secondly, excess arylamine reacts with the aromatic aldehyde to form the N-aryl aldimine B in the presence of p-toluenesulfonic acid as catalyst. Thirdly, the Mannich type

• addition of intermediate A with the acid-promoted N-aryl aldimine B gives the intermediate C. Lastly, the intramolecular electrophilic aromatic substitution at the ortho position of the activated N-aryl ring gives the final tetrahydroquinoline 1. On the other hand, the concerted imine-Diels–Alder reaction