13200-83-4Relevant articles and documents
Organocatalysis with chiral formamides: Asymmetric allylation and reduction of imines
Baudequin, Christine,Chaturvedi, Devdutt,Tsogoeva, Svetlana B.
, p. 2623 - 2629 (2007)
Simple aldimine, derived from p-nitrobenzaldehyde and 2-aminophenol, reacts with allyltrichlorosilane in the presence of chiral N-formylproline activator 5 and an L-proline additive to afford the corresponding homoallylic amine in good yield (84 %) and with moderate enantioselectivity (43 % ee). The role of the second formamide moiety in the activator is crucial to bring about the enhancement in the reaction rate and enantioselectivity, as C2-chiral bisformamide 1 promotes for the same allylation reaction in higher yield (94%) and enantioselectivity (83 % ee). Chiral monoformamide 5 (10 mol-%), with the assistance of HMPA as an additive, also catalyses the asymmetric reduction of ketimine 13 in the presence of trichlorosilane in good yield and enantioselectivity (75 %, 81 % ee). Wiley-VCH Verlag GmbH & Co. KGaA, 2007.
Synthesis of mono-and diphosphorus-substituted proline derivatives containing P–C–N fragments
Prishchenko,Livantsov,Novikova,Livantsova,Petrosyan
, p. 1846 - 1854 (2016)
Convenient methods for the synthesis of new types of mono-and diphosphorus-substituted proline derivatives containing P–C–N fragments were developed based on special pre-prepared proline-containing synthons. The corresponding organophosphorus acids including a proline fragment were also synthesized.
An eco-benign and highly efficient procedure for N-acylation catalyzed by heteropolyanion-based ionic liquids using carboxylic acid under solvent-free conditions
Chen, Zhikai,Fu, Renzhong,Chai, Wen,Zheng, Hao,Sun, Lin,Lu, Qiang,Yuan, Rongxin
, p. 2237 - 2245 (2014/03/21)
An eco-benign and highly efficient route for N-acylation of amines has been developed by treating amines with corresponding carboxylic acids in the presence of 2 mol % of heteropolyanion-based ionic liquids as catalysts under solvent-free conditions. This practical reaction could tolerate a wide range of substrates. Thus, various N-acylation products including N-acyl α-amino acid derivatives were obtained in moderate to excellent yields at 70 C to 120 C. Moreover, recycling studies revealed that heteropolyanion-based ionic liquids were easily reusable for this N-acylation. This method provides a green and much improved protocol over the existing methods.
Synthesis and reactivity of the new trimethylsilyl esters of aminomethylenebisorganophosphorus acids
Prishchenko, Andrey A.,Livantsov, Mikhail V.,Novikova, Olga P.,Livantsova, Ludmila I.,Ershov, Ivan S.,Petrosyan, Valery S.
, p. 355 - 360 (2013/09/23)
The interaction of trimethylsilyl esters of trivalent organophosphorus acids containing PH and POSiMe3 fragments in the presence of trimethylsilyl trifluoromethanesulfonate as catalyst is proposed as a convenient method for the synthesis of new trimethylsilyl esters of aminomethylenebisorganophosphorus acids with three and four coordinated phosphorus. Also the new functionalized derivatives of the aminomethylenebisphosphinic acids with substituted hydroxymethyl moieties are synthesized, and some properties of the obtained compounds are presented.
A convenient procedure for N-formylation of amines
Joseph, Sony,Das, Prasenjit,Srivastava, Bindu,Nizar, Hashim,Prasad, Mohan
, p. 929 - 931 (2013/02/25)
A simple and convenient method for the N-formylation of primary and secondary amines including amino acids has been developed utilizing formamide and sodium methoxide in moderate to excellent yield. This reagent is also utilized for one pot conversion of compounds having amino esters to N-formyl amides.
Asymmetric transfer hydrogenation of ketimines with trichlorosilane: Structural studies
Zhang, Zhiguo,Rooshenas, Parham,Hausmann, Heike,Schreiner, Peter R.
experimental part, p. 1531 - 1544 (2009/12/09)
We report structural and mechanistic studies on the organocatalytic asymmetric transfer hydrogenation of ketimines with trichlorosilane. Amines were obtained in good yields and moderate enantioselectivities. Both experiment and computation were utilized to provide an improved understanding of the mechanism. Georg Thieme Verlag Stuttgart.
A highly practical RCM approach towards a molecular building kit of spirocyclic reverse turn mimics
Bittermann, Holger,Boeckler, Frank,Einsiedel, Juergen,Gmeiner, Peter
, p. 6315 - 6322 (2008/09/19)
The development of privileged molecular scaffolds efficiently mimicking reverse turn motifs and thus increasing both binding and selectivity and enabling the elucidation of the bio-active conformation of a natural peptide has attracted remarkable interest. The frequent occurrence of proline in various turn patterns initiated the design of proline-based reverse turn mimetics. As a structural hybridization of a highly potent type VI β-turn inducer 1 with saturated spirocyclic lactams 3 efficiently mimicking type II β turns, we developed a versatile synthetic route towards unsaturated spirocyclic lactams of type 2, when Seebach's self-reproduction of chirality methodology was combined with a peptide coupling reaction and Grubbs' ring-closing metathesis. By this means, a variety of model peptides with six- up to nine-membered lactam rings were accessible following a uniform pathway. Introduction of suitably protected templates into solid-phase peptide synthesis gave rise to unsaturated spirocyclic analogues of the naturally occurring neuropeptide neurotensin. Spectroscopic investigations as well as DFT calculations on a high level of theory revealed a remarkable dependence of the reverse-turn inducing potency on the ring size. While the secondary structure of the unsaturated spirocyclic ε-lactam 12 closely agrees with the reference γlactam 3a, the unsaturated δ-lactam 11 serves as an extraordinarily potent β-turn inducer which is even superior to β-lactams of type 3b. The eight-membered unsaturated spirocyclic lactam 13 adopts a conformation almost ideally matching the prerequisites for a canonical type II β turn with the highest stability of the whole series. In contrast, the nine-membered spirolactam 14 represents a scaffold with a high conformational flexibility.
