26734-07-6Relevant academic research and scientific papers
FLP behaviour of cationic titanium complexes with tridentate Cp, O, N -ligands: Highly efficient syntheses and activation reactions of C-X bonds (X = Cl, F)
Fischer, Malte,Schwitalla, Kevin,Baues, Svenja,Schmidtmann, Marc,Beckhaus, Ruediger
, p. 1516 - 1523 (2019)
The synthesis of cationic titanium complexes 4a,b with tridentate Cp,O,N-ligand frameworks, starting from the monopentafulvene complex Cp?Ti(Cl)(π-η5:σ-η1-C5H4CR2 (CR2 = adamantylidene) (1) and bidentate O,N-ligand precursors CH3C(O)CH2CH2NR2 (R = Et, CH2Ph) (L1a,b), in a high-yielding and efficient two-step synthetic pathway is described. The β-aminoketones L1a,b were synthesized by a herein reported solvent- and catalyst-free reaction. The reaction pathway involves insertion reactions, subsequent methylations and final activations with B(C6F5)3. NMR investigations of the cationic titanium complex 4a in deuterated dichloromethane revealed an ongoing selective reaction under formation of the cationic complex 5a-d2, which is the result of C-Cl bond cleavage. In addition to selective C-Cl bond activation reactions, C(sp3)-F bonds were activated by 4a,b, pointing out the special tm-FLP nature of 4a,b.
Bismuth nitrate-catalyzed versatile Michael reactions
Srivastava, Neeta,Banik, Bimal K.
, p. 2109 - 2114 (2003)
Bismuth nitrate-catalyzed versatile Michael reaction was developed to reduce the complications that characterize the current standard Michael reaction and used for facile preparation of organic compounds of widely different structures. For example, several substituted amines, imidazoles, thio compounds, indoles, and carbamates were prepared at room temperature by following this method. In contrast with the existing methods using many acidic catalysts, this method is very general, simple, high-yielding, environmentally friendly, and oxygen and moisture tolerant. However, the promoting role of bismuth nitrate in this reaction is not understood at this time.
Nanocrystalline copper(II) oxide catalyzed aza-Michael reaction and insertion of α-diazo compounds into N-H bonds of amines
Kantam, M. Lakshmi,Laha, Soumi,Yadav, Jagjit,Jha, Shailendra
experimental part, p. 4467 - 4469 (2009/12/01)
Nanocrystalline copper(II) oxide efficiently catalyzed the conjugate addition of aliphatic amines to α,β-unsaturated compounds to produce β-amino compounds with excellent yields under mild reaction conditions. Similarly, Glycine esters are obtained in good yields by the insertion of α-diazoacetate into N-H bonds of amines. The catalyst is used for three cycles with minimal loss of activity.
Vanadyl(IV) acetate: An efficient, reusable heterogenous catalyst for Aza-Michael reaction under solvent-free conditions
Trivedi, Rajiv,Lalitha,Roy, Sarabindu
, p. 3556 - 3566 (2008/12/23)
Vanadyl(IV) acetate [VO(OAc)2] efficiently catalyzes the conjugate addition of aliphatic, aromatic amines to α,β-unsaturated carbonyl compounds in solvent-free media at room temperature to afford corresponding amino compounds in good to excellent yields. The catalyst can be recovered and reused for further cycles. Copyright Taylor & Francis Group, LLC.
1,8-Diazabicyclo[5.4.0]undec-7-ene (DBU)-promoted efficient and versatile aza-Michael addition
Yeom, Chang-Eun,Kim, Mi Jeong,Kim, B. Moon
, p. 904 - 909 (2007/10/03)
A convenient and versatile method was developed for aza-Michael addition using a substoichiometric amount of 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU). Various nitrogen nucleophiles were efficiently introduced to α,β-unsaturated carbonyl compounds employing 0.5 equiv of DBU. Furthermore, other heteroatomic nucleophiles could also be introduced successfully under the same reaction conditions.
Covert Mannich reaction via carbon transfer
Gu, Huan,Guo, Yuan,Shi, Zhen
, p. 3335 - 3338 (2007/10/03)
1,3-Dimethylbenzimidazolidine reacts with ketones, which can provide activating α hydrogens and primary or secondary amines under acidic conditions, to yield aminomethylation derivatives by a covert Mannich reaction. Copyright Taylor & Francis Group, LLC.
Cellulose-supported copper(0) catalyst for aza-Michael addition
Reddy, K. Rajender,Kumar, Nadakudity S.
, p. 2246 - 2250 (2007/10/03)
Cellulose-supported copper(0) efficiently catalyzes the aza-Michael reaction of N-nucleophiles, such as amines and imidazoles with α,β-unsaturated compounds to produce the corresponding β-amino compounds and N-substituted imidazoles in excellent yields. The reactions are facile and the recovered catalyst is used for several cycles with consistent activity. Georg Thieme Verlag Stuttgart.
Micellar solution of sodium dodecyl sulfate (SDS) catalyzes facile Michael addition of amines and thiols to α,β-unsaturated ketones in water under neutral conditions
Firouzabadi,Iranpoor,Jafari
, p. 655 - 661 (2007/10/03)
Sodium dodecyl sulfate (SDS) catalyzes facile Michael additions of amines and thiols to α,β-unsaturated ketones under neutral micellar conditions to afford the corresponding Michael adducts in good to high yields.
Improved heteroatom nucleophilic addition to electron-poor alkenes promoted by CeCl3·7H2O/NaI system supported on alumina in solvent-free conditions
Bartoli, Giuseppe,Bartolacci, Massimo,Giuliani, Arianna,Marcantoni, Enrico,Massaccesi, Massimo,Torregiani, Elisabetta
, p. 169 - 174 (2007/10/03)
(Chemical Equation Presented). Conjugate addition of heteroatom nucleophiles to carbon-carbon double bonds conjugated with a strong electron-withdrawing group is one of the most important new bond-forming strategies in synthetic organic chemistry. Among the methods for these Michael additions, Lewis acids have shown the best promoter activity, and in particular, the use of reagents impregnated over inorganic supports is rapidly increased. With the increase of environmental consciousness in chemical research, the solvent-free Michael addition has attracted our attention. In continuation of our ongoing program to develop synthetic protocols utilizing cerium trichloride, we report an extension of the CeCl3·7H2O/NaI combination supported under solvent-free conditions to promote heteroatom Michael addition. Using neutral alumina (Al2O3) as solid support permits us to circumvent some of the problems associated with the procedure where the inorganic support is silica gel. The CeCl 3· 7H2O/NaI/Al2O3 system works well for hetero-Michael additions utilizing weakly nucleophiles such as imidazoles and carbamates, and also the reaction proceeds with good yields in the case of Michael acceptors different from α,β-unsaturated carbonyl compounds. An important synthetic application of this our methodology is the intramolecular aza-Michael reaction in producing 4-piperidinone derivatives, which are of interest as synthetic intermediates toward important classes of heterocycles.
Boric acid: A novel and safe catalyst for aza-Michael reactions in water
Chaudhuri, Mihir K.,Hussain, Sahid,Kantam, M. Lakshmi,Neelima
, p. 8329 - 8331 (2007/10/03)
Boric acid efficiently catalyzes the conjugate addition of aliphatic amines to α,β-unsaturated compounds to produce β-amino compounds, with great alacrity and excellent yields, in water under mild conditions. Aromatic amines do not participate effectively in the reaction.
