1,3-Dipolar Cycloaddition of Nitrones to Gold(III)-Bound Isocyanides

Anisimova, Tatyana B, Kinzhalov, Mikhail A, Kuznetsov, Maxim L, Guedes da Silva, M Fatima C, Zolotarev, Andrey A, Kukushkin, Vadim Yu, Pombeiro, Armando JL and Luzyanin, Konstantin V ORCID: 0000-0001-9312-7139 (2016) 1,3-Dipolar Cycloaddition of Nitrones to Gold(III)-Bound Isocyanides. ORGANOMETALLICS, 35 (20). pp. 3569-3576.

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Official URL: http://dx.doi.org/10.1021/acs.organomet.6b00635

Abstract

Treatment of gold(III)-isocyanides [AuCl3(CNR1)] (R1 = Xyl 1, Cy 2, But 3) with an equimolar amount of 5,5-dimethyl-1-pyrroline-N-oxide (4) in CH2Cl2 at -74 °C leads to the generation of the heterocyclic aminocarbene species [AuCl3{C(ONaCMe2CH2CH2CbH)=NeR1}(Na-Cb)(Cb-Ne)] 8 (for R1 = But) or gold(III) complexes cis-[AuCl2{Na(CMe2CH2CH2CbNeR1)Cd=O}(Na=Cb)(Ne-Cd)] 9 and 10 (for R1 = Xyl and Cy) in good isolated yields (75-87%). DFT calculations show that deprotonation of the endocyclic CH group in the carbene ligand leads to spontaneous N-O bond cleavage, and acidity of this group is a factor controlling the different chemical behavior of 1-3 depending on the nature of substituent R1. The reaction of equimolar amounts of the aldonitrone p-TolCH=N+(Me)O- (5) or the ketonitrones Ph2C=N+(R2)O- (R2 = Ph 6, CH2Ph 7) with 1-3 in CD2Cl2 at -70 °C in air (or under N2) revealed the formation of the carbene complexes [AuCl3{C(ONMeCaH-p-Tol)=NbR1}(Ca-Nb)] (R1 = Cy 11, Xyl 12, But 13), [AuCl3{C(ONPhCaPh2)=NbR1}(Ca-Nb)] (R1 = Cy 14, But 15), or [AuCl3{C(ON(CH2Ph)CaPh2)=NbR1}(Ca-Nb)] (R1 = Cy 16, Xyl 17), as studied by 1H NMR. The reaction of 6 with 1 and of 7 with 3 did not furnish carbene products. Compounds 8-10 were characterized by ESI-MS, IR, 1D (1H, 13C{H}) and 2D (1H,1H-COSY, 1H,13C-HSQC, 1H,13C-HMBC) NMR spectroscopic techniques, and, only for 8, elemental analyses (C, H, N), while compounds 11-17 were characterized by 1D (1H, 13C{H}) and 2D (1H,13C-HSQC) NMR. Structures of compounds 8, 9, and 13 were additionally established by single-crystal X-ray diffraction.

Item Type:	Article
Depositing User:	Symplectic Admin
Date Deposited:	14 Nov 2016 08:50
Last Modified:	19 Jan 2023 07:25
DOI:	10.1021/acs.organomet.6b00635
Related URLs:	Author Publisher
URI:	https://livrepository.liverpool.ac.uk/id/eprint/3004484