121440-71-9Relevant academic research and scientific papers
Steric effects in enantioselective allylic alkylation catalysed by cationic (η3-allyl)palladium complexes bearing chiral pyridine-aziridine ligands
Ferioli, Federico,Fiorelli, Claudio,Martelli, Gianluca,Monari, Magda,Savoia, Diego,Tobaldin, Paolo
, p. 1416 - 1426 (2005)
Enantiopure N,N′-bidentate ligands (N,N′)*, containing substituted aziridine and aza-aromatic rings, were prepared from imines derived from (S)-valinol or (R)-phenylglycinol and heteroaromatic aldehydes (2-pyridine-, 6-benzyl-2-pyridine-, 2- and 8-quinoli
Pd-catalyzed asymmetric allylic alkylation with nitromethane using a chiral diaminophosphine oxide: (S,RP)-Ph-DIAPHOX. Enantioselective synthesis of (R)-preclamol and (R)-baclofen
Nemoto, Tetsuhiro,Jin, Long,Nakamura, Hiroshi,Hamada, Yasumasa
, p. 6577 - 6581 (2007/10/03)
A Pd-catalyzed asymmetric allylic alkylation with nitromethane using an aspartic acid-derived P-chirogenic diaminophosphine oxide [(S,RP)-Ph-DIAPHOX] is described. This method was successfully applied to enantioselective synthesis of (R)-precla
Palladium/BINAP(S)-catalyzed asymmetric allylic amination
Faller,Wilt, Jeremy C.
, p. 633 - 636 (2007/10/03)
(Chemical Equation Presented) The enantioselective allylic amination of acyclic allylic carbonates catalyzed by a palladium/(S)-BINAP(S) system was investigated. Amination of several substrates proceeded with high ee. Crotyl carbonates show an unusually high regioselectivity for the branched isomer. The use of (S)-TolBINAP(S) and (S)-3,5-xylyl-BINAP(S) as ligands was found to increase the enantioselectivity of the aminations. A P,S binding mode of the BINAP(S) ligand was found in an X-ray crystallographic study.
Asymmetric Synthesis Catalyzed by Chiral Ferrocenylphosphine-Transition-Metal Complexes. 8. Palladium-Catalyzed Asymmetric Allylic Amination
Hayashi, Tamio,Yamamoto, Akihiro,Ito, Yoshihiko,Nishioka, Eriko,Miura, Hitoshi,Yanagi, Kazunori
, p. 6301 - 6311 (2007/10/02)
Chiral ferrocenylphosphine ligands, represented by (R)-N-methyl-N--1-ethylamine ((R)-(S)-1a), which have a pendant side chain bearing a hydroxy group at the terminal position, were designed and used successfully for palladium-catalyzed asymmetric allylic amination of allylic substrates containing a 1,3-disubstituted propenyl structure (RCH=CHCH(X)R: R = Ph, Me, n-Pr, i-Pr; X = OCOOEt, OCOMe, OP(O)Ph2, etc.).Reaction of the allylic substrates with benzylamine in the presence of a palladium catalyst prepared in situ from Pd2(dba)3 and (R)-(S)-1a gave high yields of amination products (RCH=CHC*H(NHCH2Ph)R: >97percent ee (R) for R = Ph, 73percent ee (S) for R = Me, 82percent ee (S) for R = n-Pr, and 97percent ee (S) for R = i-Pr).The allylamines were converted into optically active amino acids and their derivatives.The high stereoselectivity of the ferrocenylphosphine ligand is expected to be caused by an attractive interaction between the terminal hydroxy group on the ligand and the incoming amine, which directs the nucleophilic attack on one of the ?-allyl carbons.The key role of the hydroxy group was supported by an X-ray structure analysis of a ?-allylpalladium complex and (31)P NMR studies.It was demonstrated that the pendant side chain on the ferrocenylphosphine ligand is directed toward the reaction site on palladium and the terminal hydroxy group is located at the position close to one of the ?-allyl carbon atoms and that ?-allyl group on the palladium coordinated with the ferrocenylphosphine 1a adopts one of the two possible conformational isomers with high selectivity (20/1) in an equilibrium state.
