131765-96-3Relevant articles and documents
Non-biaryl atropisomerism at the C-B bond in sterically hindered aminoarylboranes
Birepinte, Mélodie,Chabaud, Laurent,Pinet, Sandra,Pucheault, Mathieu,Robert, Frédéric
supporting information, p. 3007 - 3011 (2020/05/08)
Sterically hindered aminoarylboranes featuring atropisomerism about the C-B bond were prepared by addition of organomagnesium species onto readily accessible dialkylamine-borane complexes. Some of these aminoarylboranes, isosteres of vinyl styrene derivatives, were resolved by HPLC on the chiral stationary phase. They are the first examples of a non-biaryl type system which display slow rotation about a C-B bond.
METHOD FOR PRODUCING STEREOSELECTIVE EPOXYKETONE COMPOUND
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Page/Page column 28, (2014/01/17)
A novel method for producing a stereoselective epoxyketone compound is provided. A method for producing an epoxyketone compound represented by the formula (1), as represented by the following scheme, whereby it is possible to obtain an epoxyketone derivative in good yield and at high selectivity and to provide an industrially useful production method and an intermediate thereof. wherein R1 is a hydrogen atom, a linear, branched or cyclic alkyl group, an aromatic group which may have a substituent, or a heterocyclic group which may have a substituent, and R2 is a protective group for an amino group. R is a hydrogen atom or a C1-10 alkyl group, and R's may be the same or different, provided that at least one R is a C1-10 alkyl group.
When is a nanoparticle a cluster? An operando EXAFS study of amine borane dehydrocoupling by Rh4-6 clusters
Fulton, John L.,Linehan, John C.,Autrey, Tom,Balasubramanian, Mahalingam,Chen, Yongsheng,Szymczak, Nathaniel K.
, p. 11936 - 11949 (2008/09/17)
X-ray absorption fine structure (XAFS) is used to determine the structure of the rhodium cluster present during the catalyzed dehydrocoupling of amine boranes under operando conditions. We show how a variety of XAFS strategies can be used in combination with other analytical methods to differentiate homogeneous from heterogeneous systems. Analysis of the in situ XAFS spectra using a series of amine boranes (NH3BH3, R 2NHBH3, and RNH2BH3 where R = methyl, isopropyl, tert-butyl, and cyclohexyl) and rhodium catalyst precursor compounds (including chloro-(1,5-cyclooctadiene)rhodium (I) dimer, bis(1,5-cyclooctadiene)rhodium (I) trifluoromethanesulfonate, chlorodicarbonylrhodium (I) dimer, dichloro(pentamethylcylcopentadienyl)rhodium (III) dimer, hexarhodium hexadecacarbonyl, and tetrarhodium dodecacarbonyl) strongly suggest that the active catalyst species for this reaction is a homogeneous rhodium complex. Rhodium clusters containing four or six rhodium atoms (Rh4-6) bound to amine boranes are observed as the major (>99%) rhodium containing species during and after the catalyzed anaerobic dehydrocoupling. During the later stages of the reaction a nonmetallic rhodium complex precipitates in which individual Rh4-6 clusters likely form polymer chains ligated by the reaction products that have two or more ligating sites. The best fits of the XAFS data, using ab initio calculations of FEFF theory, show that the major rhodium species (80%) has each rhodium atom directly bound to three rhodium atoms with an observed bond distance of 2.73 A and to two boron atoms at 2.10 A. A minor (20%) rhodium species has each rhodium atom bound to four rhodium atoms with a bond distance of about 2.73 A and a single rhodium atom at a nonbonding distance of 3.88 A. No metallic rhodium was observed at any time during the anaerobic reaction.
