Enantioselective synthesis of tripodal cyclophanes and pyridinophanes by intramolecular [2+2+2] cycloaddition
摘要:
An enantioselective intramolecular [2+2+2] cycloaddition of 2-aminophenol-tethered triynes and diyne-nitriles proceeded using the chiral Rh catalysts, and tripodal cyclophanes and pyridinophanes with a long ansa chain (up to [16]pyridinophane) were obtained in acceptable yield with high to almost perfect ee. In the reaction of triynes, we elucidated that the oxygen atom at the alkyne terminus is essential for the excellent enantioselectivity. For the construction of cage-type molecule, the choice of rigid tether, which connects 1,6-diyne moiety with a side carbon chain having alkyne or cyano group on its terminus, was important, and 8-amino-2-naphthol moiety was also a preferable tether. (C) 2012 Elsevier Ltd. All rights reserved.
Axially Asymmetric Phosphorus Compound and Production Method Thereof
申请人:Tanaka Ken
公开号:US20090227805A1
公开(公告)日:2009-09-10
Problem to be Solved: To provide an axially asymmetric optically active biarylphosphorus compound that can easily produced without the step of optical resolution which was almost indispensable in conventional methods.
Solution: A method for producing an axially asymmetric phosphorus compound represented by the general formula (1), comprising a cycloaddition reaction of a compound having a triple bond with the use of a catalyst containing rhodium metal and an optically active bisphosphine.
(In the formula, J is an oxygen atom, a sulfur atom or BH
3
; R
1
and R
2
independently are an alkyl, cycloalkyl, aryl, alkoxy and aryloxy group; a1 and a2 independently are 0 or 1; R
3
to R
10
independently are an alkyl, cycloalkyl, aryl, alkoxy and aryloxy group; two among R
3
to R
10
may form a ring;
and * is axial asymmetry.)
Asymmetric hydrogenation of (E)-4-phenyl-3-buten-2-one by use of [Ir(binap)(cod)]BF4 and o-di-methylaminophenyldiphenylphosphine afforded (E)-4-phenyl-3-buten-2-ol in 97% chemoselectivity and in 65% enantiomeric excess. A mixed ligand iridium dihydride complex containing both BINAP and the aminophosphine ligand has been shown to be the catalytically active species.
Ligands for metals and improved metal-catalyzed processes based thereon
申请人:——
公开号:US20040171833A1
公开(公告)日:2004-09-02
One aspect of the present invention relates to ligands for transition metals. A second aspect of the present invention relates to the use of catalysts comprising these ligands in transition metal-catalyzed carbon-heteroatom and carbon-carbon bond-forming reactions. The subject methods provide improvements in many features of the transition metal-catalyzed reactions, including the range of suitable substrates, reaction conditions, and efficiency.
PROCESS FOR PRODUCING PHENYL-SUBSTITUTED HETEROCYCLIC DERIVATIVE THROUGH COUPLING USING TRANSITION METAL CATALYST
申请人:Komiyama Masato
公开号:US20110313169A1
公开(公告)日:2011-12-22
A process for efficiently producing, through few steps either a xanthine oxidase inhibitor, which is a therapeutic agent for hyperuricemia, or an intermediate therefore. The process is a novel coupling process which comprises subjecting a compound represented by formula (1) to coupling reaction with a compound represented by formula (2) in the presence of a transition metal compound to thereby obtain a compound represented by formula (3).
A process for producing an optically active amine compound, characterized by asymmetrically hydrogenating a prochiral carbon-nitrogen double bond in the presence of a ruthenium complex represented by general formula (1) or (2) (wherein P
represents an optically active diphosphine, X represents an anionic group, and Ar represents an optionally substituted arylene group).