690662-85-2Relevant academic research and scientific papers
First silver complexes of tetrahydropyrimid-2-ylidenes
Herrmann, Wolfgang A.,Schneider, Sabine K.,?fele, Karl,Sakamoto, Masato,Herdtweck, Eberhardt
, p. 2441 - 2449 (2004)
The syntheses and characterizations of homoleptic silver(I) carbene complexes of the type LAgCl (3) and [L2Ag]+ 2[Pd2Cl6]2- (4) (L=dimesityltetrahydropyrimid-2-ylidene) are described. 3 was obtained by reaction of the corresponding tetrahydropyrimidinium salt with silver(I) oxide. Subsequent reaction of 3 with Pd(CH3CN) 2Cl2 afforded complex 4. The crystal structure of 3 has been determined to be a monomer in the solid state. The 13C NMR spectra of both 3 and 4 exhibit 13 C-107,109Ag coupling in solution. Furthermore, both compounds show a downfield shift of the carbene carbon of about 20 ppm to about 205 ppm in the 13C NMR compared to five-membered ring silver(I) carbene complexes. Unlike other silver-carbene complexes, 3 does not undergo ligand exchange and can thus not be used for carbene transfer to other metals.
Stereoselective synthesis and reaction of gold(I) (Z)-enethiolates
Miyamoto, Kazunori,Hirobe, Masaya,Uchiyama, Masanobu,Ochiai, Masahito
supporting information, p. 7962 - 7965 (2015/05/13)
Bench-top-storable (Z)-enethiol reagents: gold (Z)-1-decenylthiolates were synthesized stereoselectively in high yields. They are stable upon storage at room temperature without protection from light, and react smoothly with various alkyl halides, α,β-unsaturated ketones, and electron-deficient aryl halides with excellent stereoselectivity.
Formation of a sixteen-membered ring by condensation of N,N′-dimesityl-propane-1,3-diamine with triethyl orthoformate and ammonium tetrafluoroborate
Paulsen, Andreas L.,Madsen, Robert
, p. 2051 - 2056 (2007/10/03)
Cyclocondensation of N,N′-dimesityl-propane-1,3-diamine with triethyl orthoformate and ammonium tetrafluoroborate gave as the major product macrocycle (2) under neat conditions and 1,3-dimesityl-3,4,5,6,- tetrahydropyrimidin-1-ium tetrafluoroborate with e
1,3-Dialkyl- and 1,3-Diaryl-3,4,5,6-tetrahydropyrimidin-2-ylidene Rhodium(I) and Palladium,(II)Complexes: Synthesis, Structure, and Reactivity
Mayr, Monika,Wurst, Klaus,Ongania, Karl-Hans,Buchmeiser, Michael R.
, p. 1256 - 1266 (2007/10/03)
The synthesis of novel 1,3-diaryl- and 1, 3-dialkylpyrimidin-2-ylidene-based N-heterocyclic carbenes (NHCs) and their rhodium(I) and palladium(II) complexes is described. The rhodium compounds bromo(cod)[1,3-bis(2-propyl)-3,4,5,6-tetrahydropyrimidin-2-ylidene]rhodium (7), bromo-(cod) (1,3-dimesityl-3,4,5,6-tetrahydropyrimidin-2-ylidene)rhodium (8) (cod = η4-1,5-cyclooctadiene, mesityl = 2,4,6-trimethylphenyl), chloro(cod)(1,3-dimesityl-3,4,5,6-tetrahydropyrimidin-2-ylidene)rhodium (9), and chloro-(cod) [1,3-bis(2-propyl)-3,4,5,6-tetrahydropyrimidin-2-ylidene]rhodium (10) were prepared by reaction of [{Rh(cod)Cl}2] with lithium tert-butoxide followed by addition of 1,3-dimesityl-3,4,5,6-tetrahydropyrimidinium bromide (3), 1,3-dimesityl-3,4,5,6-tetrahydropyrimidinium tetrafluoroborate (4), 1,3-di-2-propyl-3,4,5,6-tetrahydropyrimidinium bromide (6), and 1,3-di-2-propyl-3,4,5,6-tetrahydropyrimidinium tetrafluoroborate, respectively. Complex 7 crystallizes in the monoclinic space group P21/n, and 8 in the monoclinic space group P21. Complexes 9 and 10 were used for the synthesis of the corresponding dicarbonyl complexes dicarbonylchloro(1,3-dimesityl-3,4,5,6-tetrahydropyrimidin-2-ylidene)-rhodium (11), and dicarbonyl-chloro[1,3-bis(2-propyl)-3,4,5,6-tetrahydropyrimidin-2-ylidene] rhodium (12). The wavenumbers v(CO I)/v(CO II) for 11 and 12 were used as a quantitative measure for the basicity of the NHC ligand. The values of 2062/ 1976 and 2063/1982 cm-1, respectively, indicate that the new NHCs are among the most basic cyclic ligands reported so far. Compounds 3 and 6 were additionally converted to the corresponding cationic silver(I) bis-NHC complexes [Ag(1,3-dimesityl-3,4,5,6-tetrahydropyrimidin-2-ylidene)2] AgBr2 (13) and [Ag{1,3-bis(2-propyl)-3,4,5,6-tetrahydropyrimidin-2-ylidene] 2]AgBr2 (14), which were subsequently used in transmetalation reactions for the synthesis of the corresponding palladium(II) complexes Pd(1,3-dimesityl-3,4,5,6-tetrahydropyrimidin-2-ylidene) 22+ (Ag2Br2-Cl4 4-)1/2 (15) and Pd[1,3-bis(2-propyl)-3,4,5,6-tetrahydropyrimidin-2-ylidene)2]-Cl 2 (16). Complex 15 crystallizes in the monoclinic space group P2 1/c, and 16 in the monoclinic space group C2/c. The catalytic activity of 15 and 16 in Heck-type reactions was studied in detail. Both compounds are highly active in the coupling of aliphatic and aromatic vinyl compounds with aryl bromides and chlorides with turnover numbers (TONs) up to 2 000 000. Stabilities of 15 and 16 under Heck-couplings conditions were correlated with their molecular structure. Finally, selected kinetic data for these couplings are presented.
