Et2Zn/ -linked BINOL

Most recently, Shibasaki et al. reported that the Et2Zn-linked-BINOL complex 3 is an excellent catalyst for the direct asymmetric Mannich-type reaction (Fig. 2)... 

Synthesis of (2R,3S)-3-cyclohexyl-2,3-dihydroxy-1 -(2-methoxyphenyl)-1-propanone by the second generation Et2Zn/linked-BINOL = 4/1 complex... 

Direct catalytic asymmetric michael reaction of c<-hydroxyketone promoted by Et2Zn/LINKED-BINOL COMPLEX... 

Table 11.1 Direct catalytic asymmetric aldol reaction with the first generation Et2Zn/ linked-BINOL = 2/1 system.

SYNTHESIS OF (2/ .3.S )-3-CYCLOHEXYL-2,3-DIHYDROXY-1 -(2-METHOXYPHENYL)-1 -PROPANONE BY THE SECOND GENERATION Et2Zn/LINKED-BINOL = 4/1 COMPLEX WITH MS3A... 

SYNTHESIS OF (2/ )-2-HYDROXY-l-(2-METHOXY-PHENYL)-l,5-HEXANEDIONE BY THE FIRST GENERATION Et2Zn/LINKED-BINOL = 2/1 COMPLEX... 

Table 11.5 Direct catalytic asymmetric Michael reaction with the second generation Et2Zn/ linked-BINOL = 4/1 system with MS 3A (1).

The chemoselective enolate formation from hydroxyketone (245) and isomerizable aliphatic Ai-Dpp imines (246) has been described. The Et2Zn/linked-BINOL complex (247) effectively promoted the Mannich-type reaction, affording P-alkyl-P-amino-a-hydroxy ketones (248) in high enantioselectivity and good yield (Scheme 100). ... 

Harada S, Kumagai N, Kinoshita T, Matsunaga S, Shibasaki M (2003) Direct catalytic as3Tnmetric Michael reaction of hydroxyketones asymmetric Zn catalysis with a Et2Zn/linked-BINOL complex. J Am Chem Soc 125(9) 2582-2590. doi 10.1021/ja028928+... 

Shibasaki and colleagues achieved further efficient catalysis using a zinc complex as a catalyst [5,14], which was prepared from Et2Zn and linked-BINOL... 

A Et2Zn-(5, S)-linked-BINOL (21) complex has been found suitable for chemos-elective enolate formation from a hydroxy ketone in the presence of isomerizable aliphatic iV-diphenylphosphinoylimines.103 The reaction proceeded smoothly and /9- alkyl-yS-amino-a-hydroxy ketones were obtained in good yield and high enantioselectivity (up to 99% ee). A titanium complex derived from 3-(3,5-diphenylphenyl)-BINOL (22) has exhibited an enhanced catalytic activity in the asymmetric alkylation of aldehydes, allowing the reduction of the catalyst amount to less than 1 mol% without deterioration in enantioselectivity.104... 

A multinuclear Zn-binaphthoxide complex prepared from Et2Zn and the linked-BINOL 28 has recently been developed as an effective catalyst for the Michael reaction (Scheme 13) [15], The a-hydroxy acetophenone derivative 29 was a suitable substrate, reacting with the Zn complex to afford the configurationally stable Zn enolate. Reaction with a variety of enones proceeded smoothly and... 

Et2Zn solution should be released inside the THF solution of linked-BINOL... 

ZnX2," " ZnCl2," ° Zn(0Tf)2-H20," ZnF2 with diamine complex,- Et2Zn with (S, S) linked BINOL,dinuclear zinc catalyst," chiral zirconium catalyst" (e.g., Zr(0-... 

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