60683-30-9Relevant articles and documents
RE[N(SiMe3)2]3-Catalyzed Guanylation/Cyclization of Amino Acid Esters and Carbodiimides
Lu, Chengrong,Gong, Chao,Zhao, Bei,Hu, Lijuan,Yao, Yingming
, p. 1154 - 1159 (2018/02/10)
The example of rare-earth metal-catalyzed guanylation/cyclization of amino acid esters and carbodiimides is well-established, forming 4(3H)-2-alkylaminoquinazolinones in 65-96% yields. The rare-earth metal amides RE[N(TMS)2]3 (RE = Y, Yb, Nd, Sm, La; TMS = SiMe3) showed high activities, and La[N(TMS)2]3 performed best for a wide scope of the substrates.
Metal-Free and Alkali-Metal-Catalyzed Synthesis of Isoureas from Alcohols and Carbodiimides
Imberdis, Arnaud,Lefèvre, Guillaume,Thuéry, Pierre,Cantat, Thibault
supporting information, p. 3084 - 3088 (2018/02/26)
The first addition of alcohols to carbodiimides catalyzed by transition-metal-free compounds employs 1,5,7-triazabicyclo[4.4.0]dec-5-ene (TBD) and its alkali metal salts. Isoureas are obtained in short reaction times and high yields when TBDK is used as the catalyst. Control of the coordination sphere of potassium with exogenous chelating ligands, in combination with mechanistic DFT calculations, demonstrated the role and positive influence of the alkali-metal cation on the kinetics.
Highly Active Dinuclear Titanium(IV) Complexes for the Catalytic Formation of a Carbon-Heteroatom Bond
Bhattacharjee, Jayeeta,Harinath, Adimulam,Banerjee, Indrani,Nayek, Hari Pada,Panda, Tarun K.
supporting information, p. 12610 - 12623 (2018/10/09)
A series of mononuclear titanium(IV) complexes with the general composition κ3-[R{NHPh2P(X)}2Ti(NMe2)2] [R = C6H4, X = Se (3b); R = trans-C6H10, X = S (4a), Se (4b)] and [{κ2-N(PPh2Se)2}2Ti(NMe2)2] (6b) and two dinuclear titanium(IV) complexes, [C6H4{(NPh2PS)(N)}Ti(NMe2)]2 (3c) and [{κ2-N(PPh2Se)}Ti(NMe2)2]2 (6c), are reported. Dinuclear titanium(IV) complex 6c acts as an efficient catalyst for the chemoselective addition of an E-H bond (E = N, O, S, P, C) to heterocumulenes under mild conditions. The catalytic addition of aliphatic and aromatic amines, alcohol, thiol, phosphine oxide, and acetylene to the carbodiimides afforded the corresponding hydroelemented products in high yield at mild conditions with a broader substrate scope. The catalytic efficiency of the dinuclear complex depends on the cooperative effect of the TiIV ions, the systematic variation of the intermetallic distance, and the ligand's steric properties of the complex, which enhances the reaction rate. Most interestingly, this is the first example of catalytic insertion of various E-H bonds into the carbodiimides using a single-site catalyst because only the titanium-mediated insertion of E-H into a C-N unsaturated bond is reported to date. The amine and alcohol insertion reaction with the carbodiimides showed first-order kinetics with respect to the titanium(IV) catalyst as well as substrates. A most plausible mechanism for hydroelementation reaction is also proposed, based on the spectroscopic data of the controlled reaction, a time-course study, and the Hammett plot.
Synthetic method for isourea catalyzed by rare-earth compound
-
Paragraph 0083; 0085-0087, (2018/03/24)
The invention relates to a synthetic method for isourea catalyzed by a rare-earth compound. The synthetic method comprises the following steps: (1) enabling carbodiimide which is as shown in a formula (1) and alcohol which is as shown in a formula (2) to react at 25 to 60 DEG C under the catalytic action of rare earth amine to obtain the isourea, wherein the structural formulae of the formula (1) and the formula (2) are as shown in the description, wherein R1 and R2 are independently selected from C3-C8 alkyls or aryls; R3 is C1-C3 alkyls or substituted benzyls, wherein the substituted benzyls are the benzyls which contain a methyl, a naphthyl, a halogen or a pyridine ring; the rare earth amine is one of lanthanum tris[N,N-bis(trimethylsilane)amide], neodymium tris[N,N-bis(trimethylsilane)amide], samarium tris[N,N-bis(trimethylsilane)amide] or ytterbium tris[N,N-bis(trimethylsilane)amide]. According to the method, raw materials are easily obtained; the operation is simple and convenient; conditions of an application method are mild; the yield is high; the substrate application range is wide.
Actinide complexes possessing six-membered N-heterocyclic iminato moieties: Synthesis and reactivity
Ghatak, Tapas,Fridman, Natalia,Eisen, Moris S.
, p. 1296 - 1302 (2017/05/29)
A novel class of ligand systems possessing a sixmembered N-heterocyclic iminato [perimidin-2-iminato (PrRN, where R = isopropyl, cycloheptyl)] moiety is introduced. The complexation of these ligands with early actinides (An = Th and U) results in powerful catalysts [(PrRN)An(N{SiMe3)2}3] (3-6) for exigent insertion of alcohols into carbodiimides to produce the corresponding isoureas in short reaction times with excellent yields. Experimental, thermodynamic, and kinetic data as well as the results of stoichiometric reactions provide cumulative evidence that supports a plausible mechanism for the reaction.
Catalytic Addition of Alcohols into Carbodiimides Promoted by Organoactinide Complexes
Liu, Heng,Khononov, Maxim,Fridman, Natalia,Tamm, Matthias,Eisen, Moris S.
supporting information, p. 3153 - 3157 (2017/03/24)
The insertion of alcohols into carbodiimides mediated by benzimidazolin-2-iminato actinide complexes [(BimR1/R2N)AnN3] [N = N(SiMe3)2] is presented herein. Analysis of single-crystal data revealed that steric hindrance, rather than electronic properties, plays an important role in determining the accessibility for this insertion process. All actinide complexes showed excellent activities under very mild conditions. Stoichiometric reactions in combination with kinetic and thermodynamic studies allow us to propose a plausible active species and a mechanism for the catalytic cycle.
O-Phenylisourea Synthesis and Deprotonation: Carbodiimide Elimination Precludes the Reported Chapman Rearrangement
Tate, Joseph A.,Hodges, George,Lloyd-Jones, Guy C.
, p. 2821 - 2827 (2016/07/07)
The kinetics of the addition of phenol to diisopropylcarbodiimide, and reaction of the resulting N,N′-diisopropyl-O-phenylisourea with hydroxide, are reported. The isourea is generated by a slow overall termolecular equilibrium process, inhibited by isourea–phenol salt generation. In contrast to an earlier report, reaction of the isourea with hydroxide does not induce a synthetically useful 1,3-O–N (Chapman) rearrangement. Instead, deprotonation results in solvolysis by carbodiimide elimination.
Actinide-Catalyzed Intermolecular Addition of Alcohols to Carbodiimides
Batrice, Rami J.,Kefalidis, Christos E.,Maron, Laurent,Eisen, Moris S.
supporting information, p. 2114 - 2117 (2016/03/05)
The unprecedented actinide-catalyzed addition of alcohols to carbodiimides is presented. This represents a rare example of thorium-catalyzed transformations of an alcoholic substrate and the first example of uranium complexes showing catalytic reactivity with alcohols. Using the uranium and thorium amides U[N(SiMe3)2]3 and [(Me3Si)2N]2An[κ2-(N,C)-CH2Si(CH3)2N(SiMe3)] (An = Th or U), alcohol additions to unsaturated carbon-nitrogen bonds are achieved in short reaction times with excellent selectivities and high to excellent yields. Computational studies, supported by experimental thermodynamic data, suggest plausible models of the profile of the reaction which allow the system to overcome the high barrier of scission of the actinide-oxygen bond. Accompanied by experimentally determined kinetic parameters, a plausible mechanism is proposed for the catalytic cycle.
A novel synthesis of 2-alkylthiobenzothiazoles and 2-alkylthiobenzoxazoles
Yu, Yanfei,Li, Zhengning,Jiang, Lan
experimental part, p. 632 - 640 (2012/06/01)
3H-Benzothiazole-2-thione and 3H-benzoxazole-2-thione were selectively S-alkylated by use of O-alkylisoureas as the alkylating reagents. The reactions could be performed under mild reaction conditions in short reaction times, and high yields were obtained using O-primary-alkylisoureas, whereas low yields were obtained with sec-and tert-alkylisoureas.
