Insertion of Imines and Carbon Monoxide into Manganese-Alkyl Bonds: Synthesis and Structure of a Manganese--Amino Acid Derivative
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- 作者：Danny Lafrance ; Jason L. Davis ; Rajiv Dhawan ; and Bruce A. Arndtsen
- 刊名：Organometallics
- 出版年：2001
- 出版时间：March 19, 2001
- 年：2001
- 卷：20
- 期：6
- 页码：1128 - 1136
- 全文大小：129K
- 年卷期：v.20,no.6(March 19, 2001)
- ISSN：1520-6041
文摘
Two new routes have been developed to generate manganese-chelated amides from imineand carbon monoxide building blocks. The reaction of (CO)5MnR (R = CH3, Ph) with (p-tolyl)(R1)=NR2 (R1 = H, tBu; R2 = alkyl, H) results in the generation of the cyclometalatedimine complexes (CO)4Mn[
2-4-CH3-2-(C(R1)=NR2)-C6H3] in 50-84% isolated yield. However,when the reaction of (p-tolyl)(H)C=NCH3 with (CO)5MnCH3 is performed in the presence ofAlCl3, the product of sequential carbon monoxide and imine insertion is generated in 35%yield: (CO)4Mn[2-C(H)(p-tolyl)N(CH3)COCH3]. The addition of PPh3 to the latter complexresults in replacement of a carbonyl ligand and formation of the isolable fac-(CO)3(PPh3)Mn[2-C(H)(p-tolyl)N(CH3)COCH3]. In an alternative route to metal-bound amides, theoxidative addition of the N-acyl iminium salt (p-tolyl(H)C=N(CH3)COPh+Cl- to (CO)5Mn-Na+has been found to lead to the generation of the product of subsequent CO insertion, (CO)4Mn[2-COC(H)(p-tolyl)N(CH3)COPh]. The latter represents the first example of a acyl-boundtransition-metal-chelated 
-amino acid complex and has been characterized by X-raycrystallography. Preliminary reactivity studies demonstrate that (CO)4Mn[2-COC(H)(p-tolyl)N(CH3)COPh] reacts with PPh3 to generate the unchelated cis-(CO)4(PPh3)Mn[COC(H)(p-tolyl)N(CH3)COPh], while reaction with NaBH4 leads to the liberation of the amide(p-tolyl)CH2N(CH3)COPh, rather than the amino acid residue.
2-4-CH3-2-(C(R1)=NR2)-C6H3] in 50-84% isolated yield. However,when the reaction of (p-tolyl)(H)C=NCH3 with (CO)5MnCH3 is performed in the presence ofAlCl3, the product of sequential carbon monoxide and imine insertion is generated in 35%yield: (CO)4Mn[2-C(H)(p-tolyl)N(CH3)COCH3]. The addition of PPh3 to the latter complexresults in replacement of a carbonyl ligand and formation of the isolable fac-(CO)3(PPh3)Mn[2-C(H)(p-tolyl)N(CH3)COCH3]. In an alternative route to metal-bound amides, theoxidative addition of the N-acyl iminium salt (p-tolyl(H)C=N(CH3)COPh+Cl- to (CO)5Mn-Na+has been found to lead to the generation of the product of subsequent CO insertion, (CO)4Mn[2-COC(H)(p-tolyl)N(CH3)COPh]. The latter represents the first example of a acyl-boundtransition-metal-chelated -amino acid complex and has been characterized by X-raycrystallography. Preliminary reactivity studies demonstrate that (CO)4Mn[2-COC(H)(p-tolyl)N(CH3)COPh] reacts with PPh3 to generate the unchelated cis-(CO)4(PPh3)Mn[COC(H)(p-tolyl)N(CH3)COPh], while reaction with NaBH4 leads to the liberation of the amide(p-tolyl)CH2N(CH3)COPh, rather than the amino acid residue.