71458-08-7Relevant articles and documents
Highly chemoselective reduction of amides (primary, secondary, tertiary) to alcohols using SmI2/amine/H2O under mild conditions
Szostak, Michal,Spain, Malcolm,Eberhart, Andrew J.,Procter, David J.
supporting information, p. 2268 - 2271 (2014/03/21)
Highly chemoselective direct reduction of primary, secondary, and tertiary amides to alcohols using SmI2/amine/H2O is reported. The reaction proceeds with C-N bond cleavage in the carbinolamine intermediate, shows excellent functional group tolerance, and delivers the alcohol products in very high yields. The expected C-O cleavage products are not formed under the reaction conditions. The observed reactivity is opposite to the electrophilicity of polar carbonyl groups resulting from the nX → πC=O (X = O, N) conjugation. Mechanistic studies suggest that coordination of Sm to the carbonyl and then to Lewis basic nitrogen in the tetrahedral intermediate facilitate electron transfer and control the selectivity of the C-N/C-O cleavage. Notably, the method provides direct access to acyl-type radicals from unactivated amides under mild electron transfer conditions.
Preparation of samarium(II) iodide: Quantitative evaluation of the effect of water, oxygen, and peroxide content, preparative methods, and the activation of samarium metal
Szostak, Michal,Spain, Malcolm,Procter, David J.
supporting information; experimental part, p. 3049 - 3059 (2012/06/01)
Samarium(II) iodide (SmI2) is one of the most important reducing agents in organic synthesis. Synthetic chemistry promoted by SmI2 depends on the efficient and reliable preparation of the reagent. Unfortunately, users can experience difficulties preparing the reagent, and this has prevented realization of the full synthetic potential of SmI2. To provide synthetic chemists with general and reliable methods for the preparation of SmI2, a systematic evaluation of the factors involved in its synthesis has been carried out. Our studies confirm that SmI2 is a user-friendly reagent. Factors such as water, oxygen, and peroxide content in THF have little influence on the synthesis of SmI2. In addition, the use of specialized glovebox equipment or Schlenk techniques is not required for the preparation of SmI2. However, our studies suggest that the quality of samarium metal is an important factor and that the use of low quality metal is the main cause of failed preparations of the reagent. Accordingly, we report a straightforward method for activation of "inactive" samarium metal and demonstrate the broad utility of this protocol through the electron transfer reductions of a range of substrates using SmI2 prepared from otherwise "inactive" metal. An investigation into the stability of SmI2 solutions and an evaluation of commercially available solutions of the reagent is also reported.
The Synthesis and Liquid-Crystal Transition Temperatures of Some Fluoro-Substituted Benzonitriles
Kelly, Stephen M.,Schad, Hanspeter
, p. 1444 - 1452 (2007/10/02)
Various laterally fluoro-substituted benzonitriles have been prepared containing a trans-4-(n-alkyl)cyclohexane ring linked to the 4-position of the benzonitriles either through a methyleneoxy (-CH2O-) or an ethylene (-CH2CH2-) bridge.The bridging group links the benzonitrile and cyclohexane rings either directly or through an additional 1,4-bonded cyclohexane or benzene ring.The synthesis and liquid-crystal transition temperatures of these new compounds are described.In several cases the nematic-isotropic transition temperatures of F-substituted benzonitriles are found to be higher than those of the non-laterally substituted analogues.
