Synthesis and resolution of 1-(2-diphenylphosphino-1-naphthyl)isoquinoline; a PN chelating ligand for asymmetric catalysis.
摘要:
A multistep synthesis resulting in a good yield of the title compound has been developed based on the Pd-catalysed coupling of 1-chloroisoquinoline and 2-methoxy-1-naphthylboronic acid (5). The product is converted into the corresponding tfifluoromethanesulphonate (10) by successive demethylation and treatment with (CF3CO)2O, followed by a further Pd-catalysed coupling with Ph2P(O)H. The resulting phosphine oxide (11) was cleanly reduced with HSiCl3. Resolution of the phosphinamine (4) was carried out with the Pd complex derived from (R)-(+)-dimethyl(1-(1-naphthyl)ethyl)amine and PdCl2; the diastereomers were of different stabilities and solubilities and were therefore readily separated. The resolved phosphinamine, [alpha]D22 +/- 153 (c = 1, CHCl3), was enantiomerically stable on heating to 65-degrees-C for 24h. X-ray crystal structures of the adduct (16) and the Pd dimer (7) isolated during the initial coupling reaction are presented.
Rhodium-Catalyzed Enantioselective Diboration of Simple Alkenes
摘要:
Enantioselective catalytic reactions that operate directly on inexpensive unactivated alkenes are extraordinarily useful for the preparation of chiral organic building blocks and new materials. While a number of such processes have been developed, our ability to meet the intensifying demand for inexpensive stereochemically complex materials will require a significant expansion of practical catalytic asymmetric reaction methodology. In this regard, the rhodium-catalyzed enantioselective diboration reaction has been developed in order to address a number of extant problems in catalytic alkene transformation simultaneously. This process provides an enantiomerically enriched reactive dimetalated intermediate which can be converted to a variety of difunctional reaction products.
[EN] ISOCARBOSTYRIL ALKALOIDS AND FUNCTIONALIZATION THEREOF<br/>[FR] ALCALOÏDES D'ISOCARBOSTYRILE ET LEUR FONCTIONNALISATION
申请人:UNIV ILLINOIS
公开号:WO2020117894A1
公开(公告)日:2020-06-11
Enantioselective total syntheses of the anticancer isocarbostyril alkaloids (+)-7-deoxypancratistatin, (+)-pancratistatin, (+)-lycoricidine, and (+)-narciclasine are described. Our strategy for accessing this unique class of natural products is based on the development of a Ni-catalyzed dearomative trans-1,2-carboamination of benzene. The effectiveness of this dearomatization approach is notable, as only two additional olefin functionalizations are needed to construct the fully decorated aminocyclitol cores of these alkaloids. Installation of the lactam ring has been achieved through several pathways and a direct interconversion between natural products was established via a late-stage C-7 cupration. Using this synthetic blueprint, we were able to produce natural products on a gram scale and provide tailored analogs with improved activity, solubility, and metabolic stability.
Monophosphine compound, transition metal complex thereof and production method of optically active compound using the complex as asymmetric catalyst
申请人:Carreira M. Erick
公开号:US20050277772A1
公开(公告)日:2005-12-15
The present invention provides a compound represented by the formula (I):
wherein ring A is void or a benzene ring optionally having substituent(s), R
1
and R
2
are each independently a phenyl group optionally having substituent(s), a cyclohexyl group and the like, R
3
and R
4
are each independently a hydrogen atom, a halogen atom, a lower alkyl group, a lower alkoxy group and the like, and X is a residue represented by —OR
5
or —NHR
6
wherein R
5
and R
6
are a lower alkyl group optionally having substituent(s), an aralkyl group optionally having substituent(s) and the like, a asymmetric transition metal complex containing the compound as a ligand and a production method of optically active compound using the complex as an asymmetric catalyst.
Atroposelective Synthesis of PINAP via Dynamic Kinetic Asymmetric Transformation
作者:Seo‐Jung Han、Vikram Bhat、Brian M. Stoltz、Scott C. Virgil
DOI:10.1002/adsc.201801248
日期:2019.2
The atroposelective synthesis of PINAP ligands has been accomplished via a palladium‐catalyzed C−P coupling process through dynamic kinetic asymmetric transformation. These catalytic conditions allow access to a wide variety of alkoxy‐ and benzyloxy‐substituted PINAP ligands in high enantiomeric excess. The methods described in this communication afford valuable P,N ligands in good yields and high
Method for producing 5-(1-piperazinyl) -benzofuran-2-carboxamide by transition metal-catalyzed amination
申请人:——
公开号:US20030125558A1
公开(公告)日:2003-07-03
1. Process for the preparation of 5-(1-piperazinyl)benzofuran-2-carboxamide in which, as intermediate step, 5-bromosalicylaldehyde or one of its derivatives is reacted in a transition metal-catalysed amination with R
2
-piperazine, in which R
2
is as defined in claim 1.