New chiral oxazoline based-rhodium(I) catalysts: Synthesis, characterisation, heterogeneisation and applications
摘要:
New chiral oxazoline-based rhodium(l) homogeneous and heterogeneous catalysts have been prepared and fully characterised through H-1 and C-13 NMR, CP-MAS NMR and XPS. The method used for anchoring the catalyst onto silica was found particularly suitable, since the organometallic complexes remained unchanged over the procedure. The catalysts exhibited a moderate activity and enantioselectivity in hydrogenation of C=O and C=C double bond. (c) 2005 Elsevier B.V. All rights reserved.
Enantioselective Total Synthesis of Cannogenol-3-<i>O</i>-α-<scp>l</scp>-rhamnoside via Sequential Cu(II)-Catalyzed Michael Addition/Intramolecular Aldol Cyclization Reactions
作者:Bijay Bhattarai、Pavel Nagorny
DOI:10.1021/acs.orglett.7b03513
日期:2018.1.5
A concise and scalable enantioselective total synthesis of the natural cardenolides cannogenol and cannogenol-3-O-α-l-rhamnoside has been achieved in 18 linear steps. The synthesis features a Cu(II)-catalyzed enantioselective and diastereoselective Michael reaction/tandem aldol cyclization and a one-pot reduction/transposition, which resulted in a rapid (6 linear steps) assembly of a functionalized
NOVEL PROCESSES FOR THE PREPARATION OF PHENYLCYCLOPROPYLAMINE DERIVATIVES AND USE THEREOF FOR PREPARING TICAGRELOR
申请人:Khile Anil Shahaji
公开号:US20130165696A1
公开(公告)日:2013-06-27
Provided herein are novel processes for the preparation of phenylcyclopropylamine derivatives, which are useful intermediates in the preparation of triazolo[4,5-d]pyrimidine compounds. Provided particularly herein are novel, commercially viable and industrially advantageous processes for the preparation of a substantially pure ticagrelor intermediate, trans-(1R,2S)-2-(3,4-difluorophenyl)-cyclopropylamine. Provided further herein are novel acid addition salts of trans-(1R,2S)-2-(3,4-difluorophenyl)-cyclopropylamine, and process for their preparation. The intermediate and its acid addition salts are useful for preparing ticagrelor, or a pharmaceutically acceptable salt thereof, in high yield and purity.
[EN] ENANTIONSELECTIVE PROCESSES TO INSECTICIDAL 3-ARYL-3-TRIFLUOROMETHYL-SUBSTITUTED PYRROLIDINES<br/>[FR] PROCÉDÉS ÉNANTIOSÉLECTIFS POUR DES INSECTICIDES DE PYRROLIDINES 3-ARYL-3-TRIFLUOROMÉTHYL-SUBSTITUÉES
申请人:SYNGENTA PARTICIPATIONS AG
公开号:WO2013050301A1
公开(公告)日:2013-04-11
The present invention relates to processes for the enantio-selective preparation of spyrrolidine derivatives useful in the manufacture of pesticidally active compounds, as well as to intermedates in the processes. The processes include those comprising (a-i) reacting a compound of formula (Ia), formula (Ia), wherein P is alkyl, aryl or heteroaryl, each optionally substituted, wherein the heteroaryl is connected at P via a ring carbon atom; R1 is chlorodifluoromethyl or trifluoromethyl; R2 is aryl or heteroaryl, each optionally substituted; with a source of cyanide in the presence a chiral catalyst to give a compound of formula IIa, formula (IIa), wherein P, R1 and R2 are as defined for the compound of formula (Ia); and (a-ii) oxidising the compound of formula IIa with a peroxy acid, or peroxide in the presence of an acid to give a compound of formula (VI), formula (VI), wherein R1 and R2 are as defined for the compound of formula (Ia).
Construction of Janus dendrimers through a self-assembly approach involving chiral discrimination at a focal point
作者:John Zhou、Ashley M. Cole、Elizabeth M. Menuey、Kathleen V. Kilway、Shin A. Moteki
DOI:10.1039/d1cc01973b
日期:——
A strategy to build Janus dendrimers via the chirality-directed self-assembly of heteroleptic Zn(II) BOX complexes is reported. The method allows quantitative synthesis of Janus dendrimers in situ without the need for purifications. Each dendritic domain of the Janus dendrimers can be recycled upon disassembly at the focal point.
Self-assembled heteroleptic chiral ligands, assymetric catalyst systems and methods
申请人:Takacs M. James
公开号:US20060167294A1
公开(公告)日:2006-07-27
A method of synthesizing a heteroleptic, multiple metal-containing metallocyclic catalyst, particularly suited for asymmetric catalysis, comprising combining a plurality of plural functional group-containing, monodentate ligands of complementary chirality, said plural functional groups being tethered to each other by tethers in the presence of a scaffold-structural metal Ms or derivative thereof, wherein at least one functional group on each ligand combines to ligate M
s
to form a bidentate, M
s
centered ligand scaffold containing the remaining functional groups and combining said bidentate ligand scaffold with a catalytic metal M
c
or derivative thereof whereby the remaining functional groups combine to ligate M
c
, thereby forming said catalyst.