Reactions of a Cyclopentadienyl-Amidinate Titanium Benzimidamido Complex
We report the first reactivity study of a transition-metal benzimidamido complex, namely Cp Ti{PhC(NiPr)2}{NC(ArF 5NOtBu} (5, ArF5= C6F5). Reaction with CO2 and tBuNCO gave the cycloaddition products CpTi{PhC(NiPr)2}{OC(O)N(C{ArF5}NO tBu)} and CpTi{PhC(NiPr)2}{OC(N tBu)N(C{ArF5}NOtBu)} (10), respect...
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| Format: | Journal article |
| Language: | English |
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2014
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| _version_ | 1797083885871300608 |
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| author | Groom, L Russell, A Schwarz, A Mountford, P |
| author_facet | Groom, L Russell, A Schwarz, A Mountford, P |
| author_sort | Groom, L |
| collection | OXFORD |
| description | We report the first reactivity study of a transition-metal benzimidamido complex, namely Cp Ti{PhC(NiPr)2}{NC(ArF 5NOtBu} (5, ArF5= C6F5). Reaction with CO2 and tBuNCO gave the cycloaddition products CpTi{PhC(NiPr)2}{OC(O)N(C{ArF5}NO tBu)} and CpTi{PhC(NiPr)2}{OC(N tBu)N(C{ArF5}NOtBu)} (10), respectively, whereas with CS2 slow extrusion of ArF5CN from 5 occurred to ultimately form CpTi{PhC(NiPr)2}{SC(S)N(O tBu)}. Reaction of 5 with ArC(O)H (Ar = Ph, 4-C6H 4Me, 4-C6H4tBu, 4-C 6H4OMe, 4-C6H4NMe2, 4-C6H4CF3) also gave the isolable metallacyclic complexes CpTi{PhC(NiPr)2}{N(C{ArF5}NO tBu)C(Ar)(H)O} (13) via reversible [2 + 2] cycloaddition reactions. In contrast, reaction with HC(O)NMe2 formed Me 2N{NC(ArF5)NOtBu}H (16) within 1 h at room temperature. Upon heating, 10 and 13 also underwent retrocyclization, forming the organic products tBuNCNC(ArF5)NOtBu and ArC{NC(ArF5)NOtBu}H (14), respectively. Selected examples of 14 and 16 were studied by DFT and UV-visible spectroscopy. Addition of isonitriles tBuNC and XylNC (Xyl = 2,6-C6H 3Me2) to CpTi{PhC(NiPr)2}{NC(Ar) NOtBu} (Ar = ArF5 (5), 2,6-C6H 3F2 (ArF2)) afforded the σ adducts CpTi{PhC(NiPr)2}{NC(Ar)NOtBu}(CNR) (Ar = ArF5, R = tBu, Xyl (19); Ar = ArF2, R = Xyl). Subsequently, 19 formed CpTi{PhC(NiPr)2}{NC(NO tBu)C6F4N(Xyl)C}(F) (20) via C-F bond activation. Reaction of 5 with 2 equiv of B(ArF5)3 gave CpTi{PhC(NiPr)2}{ON(B{ArF5}3) C(ArF5)N(H)(B{ArF5}3)} with elimination of 2-methylpropene. © 2014 American Chemical Society. |
| first_indexed | 2024-03-07T01:47:50Z |
| format | Journal article |
| id | oxford-uuid:9907a224-12c0-45b7-ad21-49c6363f01f5 |
| institution | University of Oxford |
| language | English |
| last_indexed | 2024-03-07T01:47:50Z |
| publishDate | 2014 |
| record_format | dspace |
| spelling | oxford-uuid:9907a224-12c0-45b7-ad21-49c6363f01f52022-03-27T00:11:21ZReactions of a Cyclopentadienyl-Amidinate Titanium Benzimidamido ComplexJournal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:9907a224-12c0-45b7-ad21-49c6363f01f5EnglishSymplectic Elements at Oxford2014Groom, LRussell, ASchwarz, AMountford, PWe report the first reactivity study of a transition-metal benzimidamido complex, namely Cp Ti{PhC(NiPr)2}{NC(ArF 5NOtBu} (5, ArF5= C6F5). Reaction with CO2 and tBuNCO gave the cycloaddition products CpTi{PhC(NiPr)2}{OC(O)N(C{ArF5}NO tBu)} and CpTi{PhC(NiPr)2}{OC(N tBu)N(C{ArF5}NOtBu)} (10), respectively, whereas with CS2 slow extrusion of ArF5CN from 5 occurred to ultimately form CpTi{PhC(NiPr)2}{SC(S)N(O tBu)}. Reaction of 5 with ArC(O)H (Ar = Ph, 4-C6H 4Me, 4-C6H4tBu, 4-C 6H4OMe, 4-C6H4NMe2, 4-C6H4CF3) also gave the isolable metallacyclic complexes CpTi{PhC(NiPr)2}{N(C{ArF5}NO tBu)C(Ar)(H)O} (13) via reversible [2 + 2] cycloaddition reactions. In contrast, reaction with HC(O)NMe2 formed Me 2N{NC(ArF5)NOtBu}H (16) within 1 h at room temperature. Upon heating, 10 and 13 also underwent retrocyclization, forming the organic products tBuNCNC(ArF5)NOtBu and ArC{NC(ArF5)NOtBu}H (14), respectively. Selected examples of 14 and 16 were studied by DFT and UV-visible spectroscopy. Addition of isonitriles tBuNC and XylNC (Xyl = 2,6-C6H 3Me2) to CpTi{PhC(NiPr)2}{NC(Ar) NOtBu} (Ar = ArF5 (5), 2,6-C6H 3F2 (ArF2)) afforded the σ adducts CpTi{PhC(NiPr)2}{NC(Ar)NOtBu}(CNR) (Ar = ArF5, R = tBu, Xyl (19); Ar = ArF2, R = Xyl). Subsequently, 19 formed CpTi{PhC(NiPr)2}{NC(NO tBu)C6F4N(Xyl)C}(F) (20) via C-F bond activation. Reaction of 5 with 2 equiv of B(ArF5)3 gave CpTi{PhC(NiPr)2}{ON(B{ArF5}3) C(ArF5)N(H)(B{ArF5}3)} with elimination of 2-methylpropene. © 2014 American Chemical Society. |
| spellingShingle | Groom, L Russell, A Schwarz, A Mountford, P Reactions of a Cyclopentadienyl-Amidinate Titanium Benzimidamido Complex |
| title | Reactions of a Cyclopentadienyl-Amidinate Titanium Benzimidamido Complex |
| title_full | Reactions of a Cyclopentadienyl-Amidinate Titanium Benzimidamido Complex |
| title_fullStr | Reactions of a Cyclopentadienyl-Amidinate Titanium Benzimidamido Complex |
| title_full_unstemmed | Reactions of a Cyclopentadienyl-Amidinate Titanium Benzimidamido Complex |
| title_short | Reactions of a Cyclopentadienyl-Amidinate Titanium Benzimidamido Complex |
| title_sort | reactions of a cyclopentadienyl amidinate titanium benzimidamido complex |
| work_keys_str_mv | AT grooml reactionsofacyclopentadienylamidinatetitaniumbenzimidamidocomplex AT russella reactionsofacyclopentadienylamidinatetitaniumbenzimidamidocomplex AT schwarza reactionsofacyclopentadienylamidinatetitaniumbenzimidamidocomplex AT mountfordp reactionsofacyclopentadienylamidinatetitaniumbenzimidamidocomplex |