A novel method for the synthesis of vicinal disulfonamides promoted by metallic samarium in aqueous media
摘要:
A new method to synthesize vicinal disulfonamides by reductive coupling of N-sulfonylimines in Sm/HCl/THF has been developed and various reaction conditions have been studied. (C) 2002 Elsevier Science Ltd. All rights reserved.
Decarboxylative Mannich Reactions with Substituted Malonic Acid Half-Oxyesters
作者:Tania Xavier、Sylvie Condon、Christophe Pichon、Erwan Le Gall、Marc Presset
DOI:10.1021/acs.joc.0c02895
日期:2021.4.16
The decarboxylative Mannich reaction between imines and substituted malonicacids half-oxyesters (SMAHOs) has been developed using 1,4-diazabicyclo[2.2.2]octane (DABCO) as an organocatalyst. The reaction proceeds under simple reaction conditions and tolerates a broad range of substrates, affording general access to β2,3-aminoesters, the syn diastereomer being the major one. An alternative multicomponent
Herein, we disclose a transition-metal-free reaction system that enables α-cyanation of sulfonamides through C–H bond cleavage for the preparation of α-amino nitriles, including difficult-to-access all-alkyl α-tertiary scaffolds. More than 50 substrate examples prove a wide functional group tolerance. Additionally, its synthetic practicality is highlighted by gram-scalability and the late-stage modification
chemo- and α-regioselective asymmetric Michaeladdition of γ,γ-disubstituted α,β-unsaturatedaldehydes to nitroolefins has been presented in excellent diastereo- and enantioselectivities (dr up to >99:1, 93−96% ee) via dienamine catalysis. The Michael adducts have been efficiently converted to a number of optically pure cyclic frameworks with versatile scaffolddiversity.
N-Heterocyclic carbene-catalyzed [3+3] cyclocondensation of bromoenals with aldimines: highly enantioselective synthesis of dihydropyridinones
作者:Zhong-Hua Gao、Xiang-Yu Chen、Han-Ming Zhang、Song Ye
DOI:10.1039/c5cc04593b
日期:——
The N-heterocycliccarbene-catalyzed [3+3] cyclocondensation of bromoenals with aldimines was developed to give the corresponding dihydropyridinones in good yields with excellent enantioselectivies.
A facile and regioselective synthesis of 2,5-disubstituted pyrroles via gold-catalyzed cycloisomerization of acetylenylaziridines
作者:Dong-Dong Chen、Xue-Long Hou、Li-Xin Dai
DOI:10.1016/j.tetlet.2009.05.091
日期:2009.12
Gold-catalyzed cycloisomerization reaction of acetylenylaziridines provides 2,5-disubstituted pyrroles in high yields. The presence of protic species accelerates the reaction rate and improves the yields of pyrrole products.