Easily Accessible and Highly Tunable Bisphosphine Ligands for Asymmetric Hydroformylation of Terminal and Internal Alkenes
作者:Kun Xu、Xin Zheng、Zhiyong Wang、Xumu Zhang
DOI:10.1002/chem.201304684
日期:2014.4.7
An efficient methodology for synthesizing a small library of easily tunable and sterically bulky ligands for asymmetric hydroformylation (AHF) has been reported. Five groups of alkene substrates have been tested with excellent conversions, moderate‐to‐excellent regio‐ and enantioselectivities. Among the best result of the reported literature, application of ligand 1 c in the highly selective AHF of
mono-hydroboration and desymmetrization of symmetrical aldazines. Mechanistic studies indicate the involvement of in situ formed intermediate [(η6-p-cymene)RuCl}2(μ-H-μ-Cl)] (1a) in this selective hydroboration.
Microwave-assisted synthesis of 1-hydrazinophosphonates via the reaction of aldazines with dialkyl phosphite
作者:Babak Kaboudin、Soheil Alipour
DOI:10.1002/hc.21019
日期:——
A simple, efficient, and novel method has been developed for the synthesis of 1-hydrazinophosphonic acids from aldazines. As described below, treatment of aldazines with diethyl phosphite gives the corresponding 1-hydrazinophosphonic acids in good yields. The reaction proceeds under microwave irradiation at 110°C and neutral condition without any additives such as base, acid, or catalyst. This method
A new domino autocatalytic reaction leading to polyfunctionalized spiro[5.5]undecanes and dispiro[4.2.5.2]pentadecanes
作者:Bo Jiang、Wen-Juan Hao、Jin-Peng Zhang、Shu-Jiang Tu、Feng Shi
DOI:10.1039/b822645h
日期:——
A new domino autocatalytic reaction of imines with Meldrum's acid was described. In this reaction, a series of polycyclic spiro[5.5]undecane-1,5,9-trione and dispiro[4.2.5.2]pentadecane-9,13-dione derivatives, with remarkable diastereoselectivity, were successfully synthesized in acidic condition, and up to six new bonds were formed accompanied by the CN bond cleavage of the imines and the decomposition of Meldrum's acid, with by-product of acetohydrazide as a novel autocatalyst.
Synthesis of 1H-indazole: a combination of experimental and theoretical studies
作者:Xinzhi Chen、Shaodong Zhou、Chao Qian、Chaohong He
DOI:10.1007/s11164-012-0488-y
日期:2012.9
A new practical synthesis of 1H-indazole is presented. A previous mechanism for the cyclization step is proved to be nonfeasible and a hydrogen bond propelled mechanism is proposed. The new mechanism is suitable for similar cyclization, and a new reaction is predicted.