Abstract
<jats:p> <jats:chem-struct-wrap> <jats:chem-struct> <jats:graphic xmlns:xlink="http://www.w3.org/1999/xlink" position="anchor" xlink:href="urn:x-wiley:9780470842898:media:rn02686:nrn02686sf.001"> <jats:alt-text>image</jats:alt-text> </jats:graphic> </jats:chem-struct> </jats:chem-struct-wrap> <jats:table-wrap position="anchor"> <jats:table frame="hsides"> <jats:col/> <jats:col/> <jats:col/> <jats:tbody> <jats:tr> <jats:td> <jats:italic>[2363763‐02‐2]</jats:italic> </jats:td> <jats:td> C <jats:sub>39</jats:sub> H <jats:sub>41</jats:sub> BrFeMnN <jats:sub>2</jats:sub> O <jats:sub>5</jats:sub> P </jats:td> <jats:td>(MW 839.43)</jats:td> </jats:tr> </jats:tbody> </jats:table> </jats:table-wrap> </jats:p> <jats:p> The enantiomer of the above compound has also been prepared and used, <jats:sup> <jats:bold>2</jats:bold> </jats:sup> but at the time of writing, no CAS number has been assigned. </jats:p> <jats:p> Manganese(1+), [(1 <jats:italic>S</jats:italic> )‐1‐[bis(4‐methoxy‐3,5‐dimethylphenyl)phosphino‐κP]‐2‐[(1 <jats:italic>S</jats:italic> )‐1‐[(2‐pyridinylmethyl)amino‐κN]ethyl]ferrocene]tricarbonyl‐, bromide (1:1) is drawn for reference. <jats:chem-struct-wrap> <jats:chem-struct> <jats:graphic xmlns:xlink="http://www.w3.org/1999/xlink" position="anchor" xlink:href="urn:x-wiley:9780470842898:media:rn02686:nrn02686sf.002"> <jats:alt-text>image</jats:alt-text> </jats:graphic> </jats:chem-struct> </jats:chem-struct-wrap> </jats:p> <jats:p> InChI = <jats:ext-link xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="inchi" xlink:href="InChI=1S/C31H36N2O2P.C5H5.3CO.BrH.Fe.Mn/c1-20-15-26(16-21(2)30(20)34-6)36(27-17-22(3)31(35-7)23(4)18-27)29-13-10-12-28(29)24(5)33-19-25-11-8-9-14-32-25;1-2-4-5-3-1;3*1-2;;;/h8-18,24,33H,19H2,1-7H3;1-5H;;;;1H;;/q2*-1;;;;;+2;+1/p-1/t24-;;;;;;;/m0......./s1">1S/C31H36N2O2P.C5H5.3CO.BrH.Fe.Mn/c1‐20‐15‐26(16‐21(2)30(20)34‐6)36(27‐17‐22(3)31(35‐7)23(4)18‐27)29‐13‐10‐12‐28(29)24(5)33‐19‐25‐11‐8‐9‐14‐32‐25;1‐2‐4‐5‐3‐1;3*1‐2;;;/h8‐18,24,33H,19H2,1‐7H3;1‐5H;;;;1H;;/q2*‐1;;;;;+2;+1/p‐1/t24‐;;;;;;;/m0......./s1</jats:ext-link> </jats:p> <jats:p> InChIKey = <jats:ext-link xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="inchi" xlink:href="InChIKey=OWAMOUSQFFGMOH-YKBQGXKTSA-M">OWAMOUSQFFGMOH‐YKBQGXKTSA‐M</jats:ext-link> </jats:p> <jats:p> <jats:list list-type="simple"> <jats:list-item> <jats:p> <jats:italic>Keywords:</jats:italic> ketone reduction <jats:sup> <jats:bold>2–5</jats:bold> </jats:sup> ; ketone hydrogenation <jats:sup> <jats:bold>2–5</jats:bold> </jats:sup> ; imine hydrogenation <jats:sup> <jats:bold>6</jats:bold> </jats:sup> ; reductive amination <jats:sup> <jats:bold>6</jats:bold> </jats:sup> ; ester hydrogenation <jats:sup> <jats:bold>3,7</jats:bold> </jats:sup> ; ester reduction <jats:sup> <jats:bold>3,7</jats:bold> </jats:sup> ; conjugate reduction. <jats:sup> <jats:bold>2</jats:bold> </jats:sup> </jats:p> </jats:list-item> <jats:list-item> <jats:p> <jats:italic>Alternative Names:</jats:italic> within the field of planar chiral ferrocenes, the assignment of configuration of the planar chirality is generally done using the Schögl convention; this gives the opposite label to IUPAC or CAS stereochemical descriptors. This ensures consistency between earlier papers and with the configurations given to the commercially available precursor chemicals; these are generally assigned using Schögl convention. For a discussion of this, see reference 8. In all the cited publications concerning manganese(1+), [(1 <jats:italic>R</jats:italic> )‐1‐[bis(4‐methoxy‐3,5‐dimethylphenyl)phosphino‐κP]‐2‐[(1 <jats:italic>R</jats:italic> )‐1‐[(2‐pyridinylmethyl)amino‐κN]ethyl]ferrocene]tricarbonyl‐, bromide (1:1), the stereochemistry is assigned as ( <jats:italic>R</jats:italic> <jats:sub> <jats:italic>C</jats:italic> </jats:sub> <jats:italic>,S</jats:italic> <jats:sub> <jats:italic>P</jats:italic> </jats:sub> )‐ <jats:bold>(1)</jats:bold> . The subscript letters refer to carbon and planar chirality (i.e., the descriptor for planar chirality is inverted relative to the IUPAC or CAS naming). The ligand family has been called PFAMPy, where PFAMPy = <jats:italic>p</jats:italic> hosphino‐ <jats:italic>f</jats:italic> errocenyl‐ <jats:italic>a</jats:italic> mino‐ <jats:italic>m</jats:italic> ethyl‐ <jats:italic>py</jats:italic> ridine. </jats:p> </jats:list-item> <jats:list-item> <jats:p> <jats:italic>Solubility:</jats:italic> moderate solubility in ethanol, dichloromethane, toluene, acetone, and methanol. </jats:p> </jats:list-item> <jats:list-item> <jats:p> <jats:italic>Form Supplied in:</jats:italic> ( <jats:italic>R</jats:italic> <jats:sub> <jats:italic>C</jats:italic> </jats:sub> <jats:italic>,S</jats:italic> <jats:sub> <jats:italic>P</jats:italic> </jats:sub> )‐ <jats:bold>(1)</jats:bold> is commercially available as the ( <jats:italic>R</jats:italic> <jats:sub> <jats:italic>C</jats:italic> </jats:sub> <jats:italic>,S</jats:italic> <jats:sub> <jats:italic>P</jats:italic> </jats:sub> )‐ <jats:bold>(1)</jats:bold> enantiomer only (at the time of writing) from Solvias AG, catalogue number SK‐F604‐2m. </jats:p> </jats:list-item> <jats:list-item> <jats:p> <jats:italic>Analysis of Reagent Purity:</jats:italic> <jats:sup>31</jats:sup> P{ <jats:sup>1</jats:sup> H} NMR, <jats:sup>1</jats:sup> H NMR, <jats:sup>13</jats:sup> C NMR (the latter may require longer pulse delay due to presence of quadripolar Mn. For example, d1 = 1, and longer acquisition times to pick up the CO resonances). </jats:p> </jats:list-item> <jats:list-item> <jats:p> <jats:italic>Preparative Methods:</jats:italic> the PFAMPy (PFAMPy = <jats:italic>p</jats:italic> hosphino‐ <jats:italic>f</jats:italic> errocenyl‐ <jats:italic>a</jats:italic> mino‐ <jats:italic>m</jats:italic> ethyl‐ <jats:italic>py</jats:italic> ridine) ligand from which ( <jats:italic>R</jats:italic> <jats:sub> <jats:italic>C</jats:italic> </jats:sub> <jats:italic>,S</jats:italic> <jats:sub> <jats:italic>P</jats:italic> </jats:sub> )‐ <jats:bold>(1)</jats:bold> and ( <jats:italic>S</jats:italic> <jats:sub> <jats:italic>C</jats:italic> </jats:sub> <jats:italic>,R</jats:italic> <jats:sub> <jats:italic>P</jats:italic> </jats:sub> )‐ <jats:bold>(1)</jats:bold> are made is readily prepared from a phosphino‐ferrocenyl amine known as a PFA, available in kilogram quantities in both enantiomeric forms. The synthesis of ( <jats:italic>R</jats:italic> <jats:sub> <jats:italic>C</jats:italic> </jats:sub> <jats:italic>,S</jats:italic> <jats:sub> <jats:italic>P</jats:italic> </jats:sub> )‐ <jats:bold>(1)</jats:bold> was initially reported in cyclohexane. <jats:sup> <jats:bold>3</jats:bold> </jats:sup> Under certain conditions, or during analysis, this can deliver a second form of catalyst where the bromide counter‐ion is inner‐sphere and one carbon monoxide ligand has been replaced, i.e., of type [Mn(L)Br(CO) <jats:sub>2</jats:sub> ]. Both species are precatalysts to the active Mn‐hydride species of type [Mn(L)(CO) <jats:sub>2</jats:sub> H]. <jats:sup> <jats:bold>5</jats:bold> </jats:sup> Both give similar yields in catalysis, and hence this is of no real consequence. <jats:sup> <jats:bold>2</jats:bold> </jats:sup> A synthesis which only gives ( <jats:italic>R</jats:italic> <jats:sub> <jats:italic>C</jats:italic> </jats:sub> <jats:italic>,S</jats:italic> <jats:sub> <jats:italic>P</jats:italic> </jats:sub> )‐ <jats:bold>(1)</jats:bold> without any of this second form has been reported by simply using a sealed vessel in the preferred solvent, ethanol. <jats:sup> <jats:bold>2</jats:bold> </jats:sup> </jats:p> </jats:list-item> <jats:list-item> <jats:p> <jats:italic>Purification:</jats:italic> pure ( <jats:italic>R</jats:italic> <jats:sub> <jats:italic>C</jats:italic> </jats:sub> <jats:italic>,S</jats:italic> <jats:sub> <jats:italic>P</jats:italic> </jats:sub> )‐ <jats:bold>(1)</jats:bold> crashes out from the reaction solvent, ethanol, as it is cooled. <jats:sup> <jats:bold>2</jats:bold> </jats:sup> ( <jats:italic>R</jats:italic> <jats:sub> <jats:italic>C</jats:italic> </jats:sub> <jats:italic>,S</jats:italic> <jats:sub> <jats:italic>P</jats:italic> </jats:sub> )‐ <jats:bold>(1)</jats:bold> can be reformed by treating [Mn(L)Br(CO) <jats:sub>2</jats:sub> ] with CO if desired. <jats:sup> <jats:bold>2</jats:bold> </jats:sup> </jats:p> </jats:list-item> <jats:list-item> <jats:p> <jats:italic>Handling, Storage, and Precautions:</jats:italic> ( <jats:italic>R</jats:italic> <jats:sub> <jats:italic>C</jats:italic> </jats:sub> <jats:italic>,S</jats:italic> <jats:sub> <jats:italic>P</jats:italic> </jats:sub> )‐ <jats:bold>(1)</jats:bold> keeps for several years in a freezer under a nitrogen atmosphere. It is sufficiently air‐stable to be weighed and transferred in air. Conversion of ( <jats:italic>R</jats:italic> <jats:sub> <jats:italic>C</jats:italic> </jats:sub> <jats:italic>,S</jats:italic> <jats:sub> <jats:italic>P</jats:italic> </jats:sub> )‐ <jats:bold>(1)</jats:bold> to the neutral form [Mn(PFAMPy)Br(CO) <jats:sub>2</jats:sub> ] does take place upon storage at room temperature, especially in solution, although as noted above, this does not impact its catalysis properties. Solutions in alcoholic solvents are prone to forming some higher oxidation state paramagnetic Mn impurities over several hours. Once activated with base and hydrogen, solutions of ( <jats:italic>R</jats:italic> <jats:sub> <jats:italic>C</jats:italic> </jats:sub> <jats:italic>,S</jats:italic> <jats:sub> <jats:italic>P</jats:italic> </jats:sub> )‐ <jats:bold>(1)</jats:bold> are air and water sensitive, and hence, hydrogenation should be initiated rapidly after activation. Dry solvents should be used for catalysis, especially at lower catalyst loadings. There is no evidence of any form being pyrophoric. </jats:p> </jats:list-item> </jats:list> </jats:p>