Non-stabilized diazoalkane synthesis <i>via</i> the oxidation of free hydrazones by iodosylbenzene and application in <i>in situ</i> MIRC cyclopropanation
作者:Emmanuelle M. D. Allouche、André B. Charette
DOI:10.1039/c8sc05558k
日期:——
powerful reagents in organic synthesis, but the risks associated with their toxicity and instability often limit their uses. Herein we describe an efficient, easy-to-handle and safe batch protocol for the in situ generation and cyclopropanation of these highly reactive non-stabilized diazoalkanes through the oxidation of free hydrazones using iodosylbenzene. Numerous substituted cyclopropanes have been
Novel efficient synthesis of dibromoalkenes. A first example of catalytic olefination of aliphatic carbonyl compounds
作者:Vasily N. Korotchenko、Alexey V. Shastin、Valentine G. Nenajdenko、Elizabeth S. Balenkova
DOI:10.1039/b303221c
日期:——
A new simple and efficient one pot transformation of various aliphatic carbonyl compounds to the corresponding dibromoalkenes is described. A wide range of hydrazones of aldehydes and ketones, prepared in situ, were easily converted into dibromoalkenes by treatment with carbon tetrabromide in the presence of CuCl. The reaction proceeds under mild conditions to give the target products in good to high yields.
on the structure of the acyl azides, consecutive hydrolysis toward corresponding primary amides was observed. ‘Direct’ aminocarbonylation of the same iodoalkenes was also carried out by using ammonium carbamate as ammonia source under mild conditions. The α,β-unsaturated primary amides, formed in a chemoselective reaction, were isolated in good to excellent yields.
Synthesis of Highly Substituted Cyclobutane Fused-Ring Systems from N-Vinyl β-Lactams through a One-Pot Domino Process
作者:Lawrence L. W. Cheung、Andrei K. Yudin
DOI:10.1002/chem.200902748
日期:2010.4.6
In this contribution, aminocyclobutanes, as well as eight‐membered enamide rings, have been made from N‐vinyl β‐lactams. The eight‐membered products have been formed by a [3,3]‐sigmatropicrearrangement, whereas the aminocyclobutanes have been derivedfrom a domino [3,3]‐rearrangement/6π‐electrocyclisation process. The aminocyclobutanes have been obtained in a highly diastereoselective fashion. The
作者:Wolfgang A. Herrmann、Martina Flöel、Cornelia Weber、John L. Hubbard、Adolf Schäfer
DOI:10.1016/0022-328x(85)80052-8
日期:1985.5
The eighteen new μ-alkylidene ruthenium complexes 5a–r and 5t are very easily and cleanly obtained along the diazoalkane or the hydrazone routes that involve treatment of the dinuclear, metal-metal doubly bonded precursor compound [(η5-C5H5)Ru(μ-NO)]2 (3) either with the diazoalkanes oxidizingagent (e.g., MnO2), with the respective hydrazones. Similarly, sulfur dioxide adds cleanly to the RuRu double
十八新μ亚烷基钌配合图5a-R和5吨非常容易且干净地沿着重氮烷或涉及治疗双核,金属-金属双键前体化合物的腙途径获得[(η 5 -C 5 H ^ 5) Ru(μ-NO)] 2(3)或重氮烷烃氧化剂(例如MnO 2)和相应的。类似地,二氧化硫干净地增加的RURU双键3,由此得到配合物(μ-SO 2)[(η 5 -C 5 H ^ 5)的Ru(NO)] 2(5S)。不管卡宾桥配体的性质如何,与它们的铁类似物相比,双金属环丙烷仅表现出末端亚硝酰基配体。对于显示出不对称取代的卡宾桥的衍生物,观察到具有占主导地位的反式异构体的顺式/反式异构现象。