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Tol-BINAP-AgF

The complex -Tol-BINAP-AgF (/>-Tol-BINAP - 2,2 -bis(di-/)-tolylphosphanyl)-l,l -binapthyl) catalyzes the asymmetric addition of allylic trimethoxysilanes to aldehydes (Equation (7)).7 3 The process can provide various optically active homoallylic alcohols with high enantioselectivity (up to 96% ee) and a remarkable 7 and anti- selectivities are observed for the reaction with crotylsilanes, irrespective of the configuration of the double bond ... [Pg.949]

Independently, Yamamoto, Yanagisawa, and others reported the asymmetric aldol reaction using trimethoxysilyl enol ethers.19 The reaction was conducted with aldehydes and trimethoxysilyl enol ethers in the presence of Tol-BINAP-AgF to give the corresponding adducts with high enantioselectivities and diastereoselectiv-ities. They obtained vyra-aldol adducts as major products even when silyl enol ethers derived from cyclic ketones were used. Moreover, when a,(3-unsaturated aldehydes were employed as substrates, 1,2 adducts were obtained exclusively (Table 9.10). From an NMR study and correlation between the E Z ratio of the enol ethers and diastereoselectiviy, they proposed a cyclic transition state (Fig. 9.5). Thus, the reaction of E enol ethers proceeded via a boat form, whereas the reaction of Z enol ethers took place via a chair form. [Pg.273]

As shown in Scheme 10.132 (Section 10.3.1.2), Yamamoto et al. have recently reported highly enantioselective allylation of aromatic and a, -unsaturated aldehydes with allyltrimethoxysilane using (P)-(p-Tol-)BINAP AgF as catalyst [377]. Shibasaki et al., on the other hand, have succeeded in asymmetric allylation of acetophenone with allyltrimethoxysilane by use of a p-Tol-BINAP CuCl-TBAT co-catalyst system (up to 61% ee) [378]. [Pg.504]

Table 18.1 Enantioselective allylation of aldehydes with al-lyltrimethoxysilane (27) catalyzed by (R)-/ -Tol-BINAP- AgF complex. ... Table 18.1 Enantioselective allylation of aldehydes with al-lyltrimethoxysilane (27) catalyzed by (R)-/ -Tol-BINAP- AgF complex. ...
In contrast, Yanagisawa, Yamamoto, and coworkers have studied diverse combinations of BINAP-silver(I) catalysts and silyl enolates and found that high levels of asymmetric induction and isolated product yields were attained in the p-Tol-BINAP-AgF-catalyzed aldol reaction of trimethoxysilyl enolates (38) with aldehydes (39) in methanol (Scheme 18.15) [54]. Table 18.2 summarizes the results... [Pg.464]

Yanagisawa A, Kageyama H, Nakatsuka Y, Asakawa K, Matsumoto Y, Yamamoto H. Enantioselective addition of allylic trimethoxysilanes to aldehydes catalyzed by p-Tol-BINAP - AgF. Angew. Chem. Int. Ed. 1999 38 3701-3703. [Pg.315]

H. Yamamoto reported an enantioselective allylation of aldehydes catalyzed by AgF-p-tol-BINAP complex, [Eq. (13.24)]. High enantioselectivity was obtained... [Pg.395]


See other pages where Tol-BINAP-AgF is mentioned: [Pg.825]    [Pg.949]    [Pg.273]    [Pg.274]    [Pg.274]    [Pg.118]    [Pg.553]    [Pg.498]    [Pg.465]    [Pg.466]    [Pg.825]    [Pg.949]    [Pg.273]    [Pg.274]    [Pg.274]    [Pg.118]    [Pg.553]    [Pg.498]    [Pg.465]    [Pg.466]    [Pg.476]    [Pg.396]    [Pg.357]    [Pg.357]    [Pg.307]    [Pg.307]    [Pg.553]    [Pg.555]    [Pg.556]    [Pg.453]    [Pg.461]    [Pg.461]    [Pg.462]    [Pg.462]   
See also in sourсe #XX -- [ Pg.273 ]




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