200184-53-8Relevant academic research and scientific papers
Asymmetric lithiation trapping of N -boc heterocycles at temperatures above -78°C
Gelardi, Giacomo,Barker, Graeme,O'Brien, Peter,Blakemore, David C.
supporting information, p. 5424 - 5427 (2013/11/19)
The asymmetric lithiation trapping of N-Boc heterocycles using s-BuLi/chiral diamines at temperatures up to -20°C is reported. Depending on the N-Boc heterocycle, lithiation is accomplished using s-BuLi and (-)-sparteine or the (+)-sparteine surrogate in the temperature range -50 to -20°C for short reaction times (2-20 min). Subsequent electrophilic trapping or transmetalation-Negishi coupling delivered functionalized N-Boc heterocycles in 47-95% yield and 77:23-93:7 er. With N-Boc pyrrolidine, trapped products can be generated in ~90:10 er even at -20°C.
Asymmetric deprotonation of N -boc piperidine: React IR monitoring and mechanistic aspects
Stead, Darren,Carbone, Giorgio,O'Brien, Peter,Campos, Kevin R.,Coldham, Iain,Sanderson, Adam
supporting information; experimental part, p. 7260 - 7261 (2010/07/13)
The high yielding asymmetric deprotonation trapping of N-Boc piperidine is successfully realized using s-BuLi and a (+)-sparteine surrogate. Monitoring of the lithiation by in situ React IR allowed the direct observation of a prelithiation complex.
Aromatic amidine derivatives useful as selective thrombin inhibitors
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, (2008/06/13)
The present invention relates to a novel thrombin inhibitor which is effective even when orally administered. More specifically, the present invention relates to an aromatic amidine derivative represented by formula (I) and the salts thereof, which show potent selective inhibitory activity for thrombin in which (a), R, R1, R2, R3, A, W, Y and n are defined as described in the specification.
Enantioselective syntheses of 2-alkyl- and 2,6-dialkylpiperidine alkaloids: preparations of the hydrochlorides of (-)-coniine, (-)-solenopsin A, and (-)-dihydropinidine.
Wilkinson,Stehle,Beak
, p. 155 - 158 (2007/10/03)
[reaction: see text] Sequences of lithiation-substitution, enantioselective hydrogenation, and diastereoselective lithiation-substitution provide efficient highly enantioselective syntheses of 2-substituted and cis and trans 2,6-disubstituted piperidines.
Catalytic asymmetric hydrogenation of 1-aza-2-cycloalkene-2-carboxylates catalyzed by a trans-chelating chiral diphosphine PhTRAP-rhodium complex
Kuwano, Ryoichi,Karube, Daisuke,Ito, Yoshihiko
, p. 9045 - 9049 (2007/10/03)
A rhodium complex coordinated with a trans-chelating chiral diphosphine (S,S)-(R,R)-PhTRAP was an effective catalyst for asymmetric hydrogenation of N-acyl-1-aza-2-cycloalkene-2-carboxylates, which gave the corresponding protected cyclic α-amino acids wit
