120205-98-3Relevant academic research and scientific papers
Oxazolidinones and 2,5-Dihydrofurans via Zinc-Catalyzed Regioselective Allenylation Reactions of l -α-Amino Aldehydes
Zamani, Farzad,Pyne, Stephen G.,Hyland, Christopher J. T.
, p. 6819 - 6830 (2017/07/17)
The simultaneous control of diastereoselectivity and regioselectivity in Zn-catalyzed allenylation reactions of N-protected l-α-amino aldehydes is reported. A reversal in diastereoselectivity could be realized by variation of the α-amino aldehyde protecti
Substrate-Controlled Diastereoselectivity Reversal in NHC-Catalyzed Cross-Benzoin Reactions Using N-Boc-N-Bn-Protected α-Amino Aldehydes
Haghshenas, Pouyan,Quail, J. Wilson,Gravel, Michel
, p. 12075 - 12083 (2016/12/23)
The effectiveness of utilizing N-Bn-N-Boc-α-amino aldehydes in cross-benzoin reactions with heteroaromatic aldehydes is demonstrated. The reaction is both chemoselective and syn-selective, making it complementary to the anti-selective cross-benzoin reaction of NHBoc-α-amino aldehydes. Good diastereoselectivity is obtained for a variety of amino aldehydes, including nonhindered ones. A Felkin-Anh model can be used to rationalize the observed diastereoselectivity.
Metal-free, mild, nonepimerizing, chemo- and enantio- or diastereoselective N-alkylation of amines by alcohols via oxidation/imine-iminium formation/reductive amination: A pragmatic synthesis of octahydropyrazinopyridoindoles and higher ring analogues
Khan, Imran A.,Saxena, Anil K.
, p. 11656 - 11669 (2014/01/06)
A mild step and atom-economical nonepimerizing chemo- and enantioselective N-alkylating procedure has been developed via oxidation/imine-iminium formation/reduction cascade using TEMPO-BAIB-HEH-Bronsted acid catalysis in DMPU as solvent and a stoichiometric amount of amine. The optimized conditions were further extended for the nonenzymatic kinetic resolution of the chiral amine thus formed under nonenzymatic in situ hydrogen-transfer conditions using VAPOL-derived phosphoric acid (VAPOL-PA) as the Bronsted acid catalyst. The enantioselective cascade of the presented reaction was successfully utilized in the synthesis of octahydropyrazinopyridoindole and its higher ring analogues.
Improved stereoselectivity in intramolecular SN2′ cyclization through use of mechanistic principles
Woo, Duck Seo,Curtis-Long, Marcus J.,Seong, Hun Jeong,Tae, Hong Jun,Min, Suk Yang,Ki, Hun Park
, p. 209 - 214 (2007/10/03)
Valine and alanine were converted into the corresponding α-hydroxy-β-amino acids through intramolecular SN2′ cyclization. The novel cyclization protocol relied upon the use of N-benzyl-protected carbamates derived from α-amino acids. Georg Thie
Scope and limitations of the alkylidene carbene 1,5-CH insertion reactions of α-amino acid-derived substrates
Mapitse, Renameditswe,Hayes, Christopher J
, p. 3541 - 3542 (2007/10/03)
A range of α-amino acid-derived cyclisation precursors were synthesised from suitably protected α-amino esters, via a Dibal-H/Wittig/catalytic hydrogenation strategy and each of these was subjected to alkylidene carbene-forming conditions (lithio(trimethy
1,5-asymmetric induction in addition reaction of aldehydes with chiral allyltitaniums having an amino group at the stereogenic center. Synthesis of optically active 2,6-cis-disubstituted piperidines
Xin, Teng,Okamoto, Sentaro,Sato, Fumie
, p. 6927 - 6930 (2007/10/03)
Chiral allyltitaniums prepared from cyclic carbamate of optically active 4-aminoalk-1-en-3-ols and a Ti(O-i-Pr)4/2i-PrMgCl reagent react with aldehydes with good to excellent regio- and stereoselectivity to afford optically active 1.5-amino alcohols, from which optically active 2,6-cis- disubstituted piperidines are synthesized.
Effective and mild method for preparation of optically active α-amino aldehydes via TEMPO oxidation
Jurczak, Janusz,Gryko, Dorota,Kobrzycka, Elzbieta,Gruza, Henryk,Prokopowicz, Piotr
, p. 6051 - 6064 (2007/10/03)
The TEMPO oxidation method is successfully applied to preparation of variously protected, optically active α-amino aldehydes without racemization and in very good yield.
Diastereoselective addition of vinylmagnesium halides to variously N-mono- and N,N-diprotected L-alaninals
Gryko, Dorota,Urbanczyk-Lipkowska, Zofia,Jurczak, Janusz
, p. 4059 - 4067 (2007/10/03)
Diastereoselective C2-elongation processes of N-mono- 1a-c and N,N-diprotected 1d-f L-alaninals, using vinylmagnesium bromide and chloride, are described. A substantial difference between effects of the N-protecting groups replacing either one
Stereoselective Synthesis of (2S,3S)-Norstatine Derivatives by Addition of Lithiated Methoxyallene to Amino Aldehydes and Subsequent Ozonolysis
Hormuth, Stephan,Reissig, Hans-Ulrich,Dorsch, Dieter
, p. 121 - 128 (2007/10/02)
Addition of lithiated methoxyallene 2 to optically active N-benzyl-Boc-protected amino aldehydes 12-14 and to aldehyde 16 provides products 17-20 with good to excellent diastereoselectivity.These adducts are subsequently cleaved by ozonolysis to give α-hydroxy-β-amino acid derivatives 21-25 in good overall yield.By conversion into an oxazolidone derivative, the configuration of the major diastereomer was determined to be anti (2S,3S).Thus, the additions of 2 follow the course proposed by the Felkin-Anh model and are not ruled by chelation effects.The diastereoselective synthesis of 22 constitutes one of the simplest routes to a protected norstatine derivative. - Key Words: Methoxyallene / Allenes / Aldehydes, α-amino / Lithium compounds / Ozonolysis / Norstatine derivatives
On the stereochemical divergence in the conjugate addition of lithium dimethylcuprate/trimethylsilyl chloride to γ-alkoxy and γ-ureido α,β-unsaturated esters
Hanessian,Sumi
, p. 1083 - 1089 (2007/10/02)
A comparative study was made of the reaction of chiral nonracemic γ-alkoxy and γ-ureido-α,β-unsaturated esters with lithium dimethylcuprate in the presence of trimethylsilyl chloride. The possible origins of the anti- and syn-additions respectively are di
