Microwave-assisted total synthesis of tangutorine

Simple indole alkaloids and those with a nonrearranged monoterpenoid unit

“…255 The microwave-assisted Pictet-Spengler reaction between tryptamine and acetal was applied for the synthesis of rac-802 (Scheme 164). 256 The direct N-acylation of imine with benzoic acid was developed for the preparation of a variety of heterocycles. This method was applied for the synthesis of evodiamine (804), isolated from Evodiae fructus.…”

“…100 A facile method for the construction of a carbazole framework was developed based on the Pd-mediated Buchwald-Hartwig coupling of aniline with bromobenzene followed by The rst total synthesis of ekeberginine (251) was achieved using the Pd-mediated sequences (Scheme 61). 102 An efficient synthesis of isomukonidine ( 252), clausines L (253) and V (254), mukonidine (255), glycosinine (256), and mukonal (257) was reported, using the gold-catalyzed cyclization of indolyl-2,3-allenol 258 to carbazole 259 as a key step (Scheme 62). 103 The synthesis of 1-oxygenated carbazole alkaloids, clausine E (260) and mukonine (261), were achieved by anionic [4 + 2] annulation of lithiated furoindolones 262 with dimethyl maleate leading to carbazole 263 (Scheme 63).…”

Enantioselective Aldol Reactions of Aliphatic Aldehydes with Singh’s Catalyst

“…Reaction conditions for self-aldol reactions ( Table 1, Entries 1 -8) were optimized with monoacetal protected glutaraldehyde [28] in a reaction that has been published earlier by us [29]. The aldol reactions presented in this article (Scheme 1) were reproducible and no water elimination was observed.…”

Syntheses and Applications of Singh’s Catalyst

“…8 Wang and co-workers used Singh's prolinamide catalyst 1 for the synthesis of chiral oxazolidinone precursor 13, which is an advanced intermediate for the synthesis of the potent antibacterial agent linezolid (14) (Scheme 5). 9 They accomplished a concise total synthesis of linezolid (14) by using the organocatalytic enantioselective aldol reaction and a Beckman rearrangement.…”