SmI2-Promoted Reformatsky-Type Reaction and Acylation of Alkyl 1-Chlorocyclopropanecarboxylates
摘要:
In the presence of HMPA in THF, highly stereoselective Sml(2)-promoted substitutions of alkyl 1-chlorocyclopropanecarboxylates 1 using various ketones, aldehydes (Reformatsky-type reaction), and acyl chlorides (acylation) proceeded to give trans-adducts (2 or 5) in good to high yield with excellent trans-stereoselectivity (trans-add/cis-add = > 99/1). The Reformatsky-type reaction of 1 with aldehydes and unsymmetrical ketones proceeded with moderate diastereoselectivity (re-face-adduct/si-face-adduct = 60/40-75/25).
Calixarenes as ligands for transition-metal catalysts: a bis(calix[4]arene-11,23-dicarboxylato) dirhodium complex
作者:Jürgen Seitz、Gerhard Maas
DOI:10.1039/b110478k
日期:2002.2.12
A novel dirhodium tetracarboxylate complex is described in which two calix[4]arene macrocycles, bridged at the upper rim by a Rh-Rh unit, serve as ligands and whose solid-state structure shows an unusual coordination of a toluene molecule in the axial position at each rhodium atom.
Diruthenium(I,I) saccharinate complexes: Synthesis, molecular structure, and evaluation as catalysts for carbenoid reactions of diazoacetates
作者:Stefan Buck、Gerhard Maas
DOI:10.1016/j.jorganchem.2006.02.013
日期:2006.6
The dinuclear ruthenium complexes [Ru2(μ-sac)2(CO)6] (1), [Ru2(μ-sac)2(CH3CN)2(CO)4] (3), [Ru2(μ-sac)2(CO)5(PPh3)] (4) and [Ru2(μ-sac)2(CO)4(PPh3)2] (5) as well as the tetranuclear ruthenium complex [Ru2(μ-sac)2(CO)5]2 (2) (sac = saccharinate, C7H4NO3S−) were synthesized starting from Ru3(CO)12 and saccharin. X-raycrystalstructure analysis of 1, 3A × p-xylene, 4 × CH2Cl2 and 5 × 3CH2Cl2 showed that