Enantioselective Synthesis of Hemiaminals via Pd-Catalyzed C–N Coupling with Chiral Bisphosphine Mono-oxides
摘要:
A novel approach to hemiaminal synthesis via palladium-catalyzed C-N coupling with chiral bisphosphine mono-oxides is described. This efficient new method exhibits a broad scope, provides a highly efficient synthesis of HCV drug candidate elbasvir, and has been applied to the synthesis of chiral N,N-acetals.
The air-stable chiral diphosphine chelate ligand R,R-QuinoxP (L; 2,3-bis(tert-butylmethylphosphino)quinoxaline) as developed by Imamoto et al. has been used to obtain the crystallographically characterized complexes (L)PtCl2 (1), (L)PdCl2 (2), and (L)Re(CO)3Cl (3). Coordination was found to occur via the P donor atoms, as indicated by crystal structures and NMR studies; the quinoxaline N donors do not
Direct intramolecular carbon(sp<sup>2</sup>)–nitrogen(sp<sup>2</sup>) reductive elimination from gold(<scp>iii</scp>)
作者:Jong Hyun Kim、R. Tyler Mertens、Amal Agarwal、Sean Parkin、Gilles Berger、Samuel G. Awuah
DOI:10.1039/c8dt05155k
日期:——
carbon donor ligands results in reductiveelimination. Combined experimental and computational investigations lead to the first evidence of a direct intramolecular C(sp2)–N(sp2) bond formation from a monomeric [(C^N)AuCl2] gold(III) complex. We show that bidentate ligated Au(III) systems bypass transmetallation to form C(sp2)–N(sp2) species and NHC–Au–Cl. Mechanistic investigations of the reported transformation
α- and β-Functionalized Ketones from 1,3-Dienes and Aldehydes: Control of Regio- and Enantioselectivity in Hydroacylation of 1,3-Dienes
作者:Mahesh M. Parsutkar、T. V. RajanBabu
DOI:10.1021/jacs.1c06245
日期:2021.8.18
oxidative dimerization mechanism that involves a Co(I)/Co(III) redox cycle that appears to be initiated by a cationic Co(I) intermediate. Studies of reactions using isolated neutral and cationic Co(I) complexes confirm the critical role of the cationic intermediates in these reactions. Enantioselective 1,2-hydroacylation of 2-trimethylsiloxy-1,3-diene reveals a hitherto undisclosed route to chiral siloxy-protected
2, 3-Bis(dialkylphosphino)pyrazine derivative, process of producing the same, and metal complex having the same as ligand
申请人:Imamoto Tsuneo
公开号:US20070021610A1
公开(公告)日:2007-01-25
An optically active 2,3-bis(dialkylphosphino)pyrazine derivative represented by formula (1) is disclosed. The pyrazine derivative is preferably a quinoxaline derivative represented by formula (2). In formula (1) and (2), R
1
is preferably a t-butyl or adamantyl group, and R
2
is preferably a methyl group.
wherein R
1
is a substituted or unsubstituted, straight chain or branched alkyl group having 2 to 10 carbon atoms; R
2
is a substituted or unsubstituted, straight chain or branched alkyl group having fewer carbon atoms than R
1
; and R
3
and R
4
, which may be the same or different, are each a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, or R
3
and R
4
are taken together to form a saturated or unsaturated ring.
wherein R
1
and R
2
are as defined above; and R
5
is a monovalent substituent.
The present invention is intended to provide a method for efficiently producing and providing a compound having a spirooxindole skeleton, for example, a compound having a spirooxindole skeleton and having antitumor activity that inhibits the interaction between Mdm2 protein and p53 protein, or an intermediate thereof, using an asymmetric catalyst. A compound having an optically active tricyclic dispiroindole skeleton is efficiently obtained through a catalytic asymmetric 1,3-dipolar cycloaddition reaction using ketimine as a reaction substrate and using a chiral ligand and a Lewis acid.