121440-83-3

Upstream product

• 790681-48-0 3-penten-2-yl ethyl carbonate 
• 100-46-9 benzylamine 
• 31001-80-6 3-penten-2-yl acetate 
• 1569-50-2 3-penten-2-ol 
• 121471-32-7 (E)-1-Methyl-2-butenyl diphenylphosphinate 

Relevant academic research and scientific papers

Towards continuous flow, highly enantioselective allylic animation: ligand design, optimization and supporting

A family of enantiopure diphenylphosphinooxazolines (PHOX) containing in their structures a sterically tunable alkoxymethyl group (-CH2OR) has been optimized for the palladium-catalyzed asymmetric allylic amination. The optimal catalyst (R=CH3), depicting very high catalytic activity and broad scope applicability, has been further modified to include an ω-alkynyloxy substituent of variable length for polymer supporting via click chemistry, and has been anchored onto slightly cross-linked azidomethyl poly(styrene). The length of a polymethylene chain connecting the PHOX unit with the 1,2,3-triazole linker has been optimized, and the first polymer-supported PHOX ligands for the highly enantioselective allylic amination have been prepared in this manner. Conditions for catalyst recovery and reuse in microwave-promoted amination reactions have been established, and the system has been finally adapted to continuous flow operation.

Palladium/BINAP(S)-catalyzed asymmetric allylic amination

(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.

Application of chiral mixed phosphorus/sulfur ligands to palladium-catalyzed allylic substitutions

A modular approach to the synthesis of a class of mixed phosphorus/sulfur ligands was designed to identify important ligand structural features for enantioselective palladium-catalyzed allylic subsitutions of acyclic and cyclic ayllic esters. After a systematic variation of the ligand substituents at sulfur, phosphorus, and the ligand backbone, ligand 11k was found to be optimal in the palladium-catalyzed allylic substitution of 1,3-diphenylpropenyl acetate with dimethyl malonate or benzylamine in high yield and excellent enantioselectivity (95-98% ee). A similar optimization of the mixed phosphorus/sulfur ligand for the palladium-catalyzed allylic substitution of cycloalkenyl acetates showed that 49g afforded the highest enantioselectivities (91-97% ee). Application of this methodology to heterocyclic substrates was developed as an efficient approach to the enantioselective synthesis of 3-substituted piperidines and dihydrothiopyrans. Models for asymmetric induction are discussed based on the absolute stereochemistry of the products, X-ray crystallographic data, and NMR spectroscopic data for relevant π-allyl complexes.

Asymmetric allylic substitution reaction with nitrogen and oxygen nucleophiles using monodentate chiral phosphine, 9-PBN

Asymmetric allylic substitution reactions between 1,3-diphenyl-2-propenyl acetate and various hetero nucleophiles were efficiently carried out using the catalysts derived from the monodentate phosphine ligands, (1R, 2S, 5R, 6S)-2,6-dimethyl-9-phenyl-9-phosphabicyclo[3.3.1] nonane and its enantiomer ((-)- and (+)-9-PBNs), and palladium (0).

A Widely Applicable Chiral Auxiliary, cis-2-Amino-3,3-dimethyl-1-indanol: Conversion to a Novel Phosphorus-Containing Oxazoline and Its Application as a Highly Efficient Ligand for the Palladium-Catalyzed Enantioselective Allylic Amination Reaction

A chiral amino alcohol, cis-2-amino-3,3-dimethyl-1-indanol (2), was converted into the corresponding enantiomerically pure phosphorus-containing oxazoline 4. Oxazoline 4 was found to be an efficient ligand for palladium-catalyzed enantioselective allylic amination reactions: In the amination reaction of (E)-1,3-diphenyl-2-propen-1-yl acetate (7a), 4 was found to be more efficient than the similar ligands 1a-c, derived from valinol, tert-leucinol, etc. Other 1,3-bis(p-substituted aryl)-2-propen-1-y] acetates were also converted to the corresponding amines in a similar manner and with excellent enantioselectivity. In the amination reaction of 1-alkyl-3,3-diphenyl-2-propen-1-yl acetates 11, the correponding amines 12 were obtained with excellent enantioselectivity when acetic acid was added to the reaction system.

Asymmetric Synthesis Catalyzed by Chiral Ferrocenylphosphine-Transition-Metal Complexes. 8. Palladium-Catalyzed Asymmetric Allylic Amination

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.