monophosphoramidite ligands 6 a–m were synthesized, which demonstrated excellent enantioselectivity in RhI‐catalyzed asymmetric hydrogenation of a dehydro amino acid methyl ester. Ligands 6 a–m were also successfully applied in the RhI‐catalyzed enantioselective [4+2] cycloaddition of α,β‐unsaturated imines with isocyanates, which afforded the corresponding pyrimidinones in good yields (60–92 %) with high enantioselectivities
合成了一系列带有2,2'-二甲基,环戊基或环己基稠合环的1,1'-螺代双茚满-7,7'-二醇(SPINOL)类似物,并通过X阐明了它们的独特结构特征射线晶体学。在这些支架的基础上,合成了手性单亚磷酰胺配体6 a – m,在Rh I催化的脱氢氨基酸甲酯的不对称氢化反应中表现出优异的对映选择性。配体6 a – m也成功应用于Rh Iα,β-不饱和亚胺与异氰酸酯的催化对映选择性[4 + 2]环加成反应,可提供相对应的嘧啶酮,收率高(60-92%),对映选择性高(75-92%ee)。
Solvent-Free Crossed Aldol Condensation of Cyclic Ketones with Aromatic Aldehydes Assisted by Microwave Irradiation
作者:Abbas A. Esmaeili、Mehri Salimi Tabas、Mohammad A. Nasseri、Foad Kazemi
DOI:10.1007/s00706-004-0256-9
日期:2005.4
A fast alumina-promoted crossed aldol-condensation reaction of aldehydes and cyclic ketones under microwave irradiation is described. This process is simple, efficient, and environmentally benign and proceeds in fairly high yield without any self-condensation.
Water promoted C–C bond cleavage: facile synthesis of 3,3-bipyrrole derivatives from dienones and tosylmethyl isocyanide (TosMIC)
作者:Rong Wang、Shun-Yi Wang、Shun-Jun Ji
DOI:10.1039/c3ob42570c
日期:——
A simple and highly efficient synthetic strategy to access 3,3-bipyrrole derivatives by the reaction of dienone derivatives with TosMIC is reported. The reaction involves a van Leusen's pyrrole synthesis followed by an unusual CâC bond cleavage in the presence of water under mild conditions.
本报告介绍了一种通过二烯酮衍生物与 TosMIC 反应获得 3,3-联吡咯衍生物的简单而高效的合成策略。该反应涉及 van Leusen 的吡咯合成,然后在温和的条件下,在有水存在的情况下进行不寻常的 CâC 键裂解。
Synthesis of New Pyrazoline-Nucleoside Analogue Derivatives
作者:M. Azouz、K. Lammara、M. Benallia、H. Guenane
DOI:10.1080/15257770.2013.786834
日期:2013.1
In this work, a synthesis of pyrazoline nucleosides analogues is presented, using the stereospecific sodium salt glycosylation procedure. In the first step, chalcones were prepared using Claisen-Schmidt reaction by reacting benzaldehyde with enolizable ketones in ethanolic NaOH solutions. Next, these chalcones were immediately reacted with hydrazine hydrochloride in the presence of dry methanol to obtain the corresponding 2-pyrazolines. Finally, the coupling of the pyrazolines with 1-chloro-arabinofuranose leads to different beta-nucleosides as the major product (13-17) in good yields.The structures of these derivatives were characterized by infrared and (HNMR)-H-1 spectroscopy and mass spectrometry.
Buu-Hoi; Xuong, Bulletin de la Societe Chimique de France, 1958, p. 758,760