New Metal-Only Lewis Pairs: Elucidating the Electronic Influence of <i>N</i>-Heterocyclic Carbenes and Phosphines on the Dative Pt-Al Bond

The synthesis and full characterization of a new heteroleptic <i>N</i>-heterocyclic carbene (NHC)–phosphine platinum(0) complex and formation of its corresponding alane adduct is reported. The influence of the ligands on the Lewis basic properties was studied via multinuclear NMR-spectroscopy, X-ray analyses, and density functional theory (DFT) calculations. Consistently, the effect of changing the halogens upon the Lewis acid properties of aluminum halides was studied by X-ray analysis and DFT calculations

New Metal-Only Lewis Pairs: Elucidating the Electronic Influence of <i>N</i>-Heterocyclic Carbenes and Phosphines on the Dative Pt-Al Bond

The synthesis and full characterization of a new heteroleptic <i>N</i>-heterocyclic carbene (NHC)–phosphine platinum(0) complex and formation of its corresponding alane adduct is reported. The influence of the ligands on the Lewis basic properties was studied via multinuclear NMR-spectroscopy, X-ray analyses, and density functional theory (DFT) calculations. Consistently, the effect of changing the halogens upon the Lewis acid properties of aluminum halides was studied by X-ray analysis and DFT calculations

Metathesis Reactions of a Manganese Borylene Complex with Polar Heteroatom–Carbon Double Bonds: A Pathway to Previously Inaccessible Carbene Complexes

A comprehensive study has been carried out to investigate the metathesis reactivity of the terminal alkylborylene complex [(η⁵-C₅H₅)­(OC)₂MnB­(<i>t</i>Bu)] (<b>1</b>). Its reactions with 3,3′,5,5′-tetrakis­(trifluoromethyl)­benzophenone, 4,4′-dimethylbenzophenone, 2-adamantanone, 4,4′-bis­(diethylamino)­benzophenone, and 1,2-diphenylcyclopropen-3-one afforded the metathesis products [(η⁵-C₅H₅)­(OC)₂MnCR₂] (R = C₆H₃-3,5-(CF₃)₂ <b>3a</b>, C₆H₄-4-Me <b>3b</b>, C₆H₄-4-NEt₂ <b>3d</b>; CR₂ = adamantylidene <b>3c</b>, cyclo-C₃Ph₂ <b>3e</b>). The cycloaddition intermediates were detected by NMR spectroscopy from reactions involving ketones with more electron-withdrawing substituents. The reaction of <b>1</b> with dicyclohexylcarbodiimide (DCC) only proceeds to form the cycloaddition product [(η⁵-C₅H₅)­(OC)₂Mn­{κ²-<i>C</i>,<i>B</i>-C­(NCy)­N­(Cy)­B­(<i>t</i>Bu)}] (<b>4</b>), which upon warming, rearranges to afford complex [(η⁵-C₅H₅)­(OC)₂Mn­{CN­(Cy)­B­(<i>t</i>Bu)­CN­(Cy)}] (<b>5</b>). The reaction of <b>1</b> with triphenylphosphine sulfide SPPh₃ also yields the metathesis product [(η⁵-C₅H₅)­(OC)₂Mn­(PPh₃)] via an intermediate which is likely to be a η²-thioboryl complex [(η⁵-C₅H₅)­(OC)₂Mn­{(η²-SB­(<i>t</i>Bu)}] (<b>6</b>). Similar reactions have been studied using an iron borylene complex [(Me₃P)­(OC)₃FeB­(Dur)] (Dur = 2,3,5,6-tetramethylphenyl, <b>9</b>). Extensive computational studies have been also carried out to gain mechanistic insights in these reactions, which provided reaction pathways that fit well with the experimental data

Metathesis Reactions of a Manganese Borylene Complex with Polar Heteroatom–Carbon Double Bonds: A Pathway to Previously Inaccessible Carbene Complexes

A comprehensive study has been carried out to investigate the metathesis reactivity of the terminal alkylborylene complex [(η⁵-C₅H₅)­(OC)₂MnB­(<i>t</i>Bu)] (<b>1</b>). Its reactions with 3,3′,5,5′-tetrakis­(trifluoromethyl)­benzophenone, 4,4′-dimethylbenzophenone, 2-adamantanone, 4,4′-bis­(diethylamino)­benzophenone, and 1,2-diphenylcyclopropen-3-one afforded the metathesis products [(η⁵-C₅H₅)­(OC)₂MnCR₂] (R = C₆H₃-3,5-(CF₃)₂ <b>3a</b>, C₆H₄-4-Me <b>3b</b>, C₆H₄-4-NEt₂ <b>3d</b>; CR₂ = adamantylidene <b>3c</b>, cyclo-C₃Ph₂ <b>3e</b>). The cycloaddition intermediates were detected by NMR spectroscopy from reactions involving ketones with more electron-withdrawing substituents. The reaction of <b>1</b> with dicyclohexylcarbodiimide (DCC) only proceeds to form the cycloaddition product [(η⁵-C₅H₅)­(OC)₂Mn­{κ²-<i>C</i>,<i>B</i>-C­(NCy)­N­(Cy)­B­(<i>t</i>Bu)}] (<b>4</b>), which upon warming, rearranges to afford complex [(η⁵-C₅H₅)­(OC)₂Mn­{CN­(Cy)­B­(<i>t</i>Bu)­CN­(Cy)}] (<b>5</b>). The reaction of <b>1</b> with triphenylphosphine sulfide SPPh₃ also yields the metathesis product [(η⁵-C₅H₅)­(OC)₂Mn­(PPh₃)] via an intermediate which is likely to be a η²-thioboryl complex [(η⁵-C₅H₅)­(OC)₂Mn­{(η²-SB­(<i>t</i>Bu)}] (<b>6</b>). Similar reactions have been studied using an iron borylene complex [(Me₃P)­(OC)₃FeB­(Dur)] (Dur = 2,3,5,6-tetramethylphenyl, <b>9</b>). Extensive computational studies have been also carried out to gain mechanistic insights in these reactions, which provided reaction pathways that fit well with the experimental data