Über die gemeinsame Einwirkung von elementarem Schwefel und gasförmigem Ammoniak auf Ketone VIII. Die Kondensation von α‐Mercaptoaldehyden mit Oxo‐Verbindungen und Gasförmigem Ammoniak zu Thiazolinen‐Δ

α‐Amino Acid‐Isosteric α‐Amino Tetrazoles

“…[28] Moreover, it can be readily synthesized in good yields in one pot by another MCR, the Asinger-3CR of acetone, ammonia and mercaptoacetaldehyde dimer 39 (Scheme 9). [28, 29] The simple reaction of Walborsky's isocyanide 8 with TMSN 3 and 40 yielded 5w in moderate yields. Heating the Ugi product 5w at reflux in ethanolic HCl provided the Cys analogue 6w in good yield by N,S-acetal and tetrazole deprotection (Scheme 10 and Table 4).…”

“…Thiazolidine 40 is a bench‐stable liquid, which is well known to work as a component in the classical Ugi‐4CR . Moreover, it can be readily synthesized in good yields in one pot by another MCR, the Asinger‐3CR of acetone, ammonia and mercaptoacetaldehyde dimer 39 (Scheme ) . The simple reaction of Walborsky's isocyanide 8 with TMSN 3 and 40 yielded 5 w in moderate yields.…”

Diastereoselective Lewis acid mediated hydrophosphonylation of heterocyclic imines: a stereoselective approach towards α-amino phosphonates

“…Accordingly, the minor diastereomer is indicated by 'mi'. The following compounds were synthesized according to known procedures: rac-7λ 5 -dinaphtho[2,3-d:2,3-f][1,3,2]dioxaphosphepin-7-one (= BINOL-phosphonate, 1), 37 5,5-dimethyl-1,3,2λ 5 -dioxaphosphinan-2-one (2a), 38 diisopropyl phosphonate (2b), 39 2,2,5,5tetramethyl-2,5-dihydro-1,3-thiazole (3a), 26 2,2-dimethyl-1thia-4-azaspiro [4.5]dec-3-ene (3b), 26 2,2-dimethyl-1-thia-3azaspiro [4.5]dec-3-ene (3c), 40 7-thia-14-azadispiro[5.1.5.2]pentadec-14-ene (3d), 40 1-thia-4-azaspiro[4.5]dec-3-ene (3e), 41 rac-2,2-dimethyl-5-isopropyl-2,5-dihydro-1,3-thiazole (4), 42 rac-2-phenyl-5,5-dimethyl-2,5-dihydro-1,3-thiazole (5a), 41 rac-2-tert-butyl-5,5-dimethyl-2,5-dihydro-1,3-thiazole (5d), 43 rac-2-tert-butyl-1-thia-3-azaspiro[4.5]dec-3-ene (5e), 44 rac-2isopropyl-1-thia-3-azaspiro [4.5]dec-3-ene (5f). 45 General procedure for the BF 3 -catalyzed hydrophosphonylation of 2,5-dihydro-1,3-thiazoles 3-5 (GP1)…”

Cysteine Chemistry in Connection with Abiogenesis

“…We synthesized dimer 3 by the previously known reaction of chloroacetaldehyde with NaSH, and reacted it with NaCN (Scheme ). The reaction was quick and the expected cyanohydrine 10 was identified as the only product ( 1 H, 13 C NMR and mass spectrometry).…”