Binaphthyl-diamine

In 1999, Shi el al. showed that a diphenylthiophosphoramide derived from (li ,2i )-l,2-diaminocyclohexane could be used as a ligand in the catalytic asymmetric addition of ZnEt2 to aldehydes in the presence of Ti(Oi-Pr)4, providing the corresponding alcohols in enantioselectivities of 40-50% ee (Scheme 3.20). Another class of new ligands such as the phenylthio-phosphoramide of (7 )-1,1 -binaphthyl-2,2 -diamine was developed by the same group, and further tested as a ligand in the same conditions (Scheme 3.20). ... 

The use of chiral C2-symmetric trifluoromethanesulfonamides derived from (i )-1,1 -binaphthyl-2,2 -diamine in similar reactions to those described above has led to the formation of the expected alcohols with enantioselectivities of 43-54% ees. Better enantioselectivities were observed by Paquette et al, resulting from the use of chiral C2-symmetric VERDI (verbenone dimers) disulfonamides derived from the dimerisation of (+ )-verbenone. Stereoselectivity levels ranging from 72 to 98% ee were observed, depending on the structural characteristics of the aldehyde (Scheme 3.45). ... 

Shi and Wang reported that the catalyst generated from AgOTf and a chiral diphenylthiophosphoramide ligand, which was prepared from chiral 1,1 -binaphthyl-2, 2 -diamine, could promote the allylation reaction of allyltributyltin and aromatic aldehydes (Table 9.4).8 Thus, the reaction of allyltributyltin and aldehyde in the presence of AgOTf and chiral diphenylthiophosphoramide gave the corresponding adducts with up to 98% ee. 

Fig. 9 Separation of enantiomers of 1,1 -binaphthyl-2,2 -diamine with TMA-P-CDs of average degree of substitution 1.0 (a) and 3.5 (b) (reproduced from [160])...

The involvement by Yus et al. of other diamines, such as the binaphthyl-diamine derivative depicted in Scheme 4.7, did not produce any improvement for the enantioselective addition of ZnEt2 to acetophenone, since the corresponding alcohol was produced with an enantioselectivity of 82% ee instead of 86% ee obtained with the corresponding mem-xylenediamine derivative. ... 

Our group reported a class of chiral picolinamides, derived from enantiomerically pure chiral diamines for trichlorosilane-mediated reactions [50]. Picolinic acid was condensed with (7 )-A,A -dimethyl amino binaphthyl diamine to afford catalyst 16 in 73% yield after chromatographic purification [51]. Good results were obtained... 

Benaglia and coworkers have developed a number of chiral ligands based on binaphthyl diamine (190) for CuOTf-catalyzed additions of terminal alkynes to preformed imines (Scheme 17.39) [51]. In a screen of the parent binaphthyl diamine (190) and N-alkylated derivatives, ligand (190) was found to provide moderate enantioselectivity in the addition of phenylacetylene (189) to imine (188). The selectivity could be improved by using bis-imine derivative (191) as the chiral ligand in the reaction [52]. 

The products 4 are formed as racemic mixtures, but can be resolved by recrystallization of diastereomeric salts.23 - 25 Syntheses starting from optically active biphenyl compounds are also known.26 -28 l,l -Binaphthyl-2,2 -diamine(5) can be transformed to the dinaphtho[1,4]di-azocine 6 by melting with benzil.29... 

Related catalysts include both a chiral BINAP-type phosphine and a chiral diamine ligand. A wide range of aryl ketones gave more than 95% enantioselectivity when substituted-l,l -binaphthyl and ethylene diamines were used.52... 

Later, several other copper catalysts bearing dinitogen ligands [bipyridine derivatives (76),232,233 diamines (77),234 bis(azaferrocene) (78),235 bisferrocenyldiamine (79),159 and bis(oxazoyl) binaphthyl (80)236] have been introduced (Scheme 62), but asymmetric induction by them does not exceed that by complex (75). 

Tanner et al. (58) investigated the asymmetric aziridination of styrene using bis(aziridines) such as 85. Low induction is observed with these ligands, Eq. 64. A significant electronic effect was noted with the p-fluoro-phenyl substituted bis(az-iridine) 85c (59). A binaphthyl-derived diamine was used as a ligand for the copper-catalyzed aziridination of dihydronaphthalene (81). The product was formed in 21% ee and 40% yield, Eq. 65. Other structurally related ligands proved to be less selective in this reaction. 

The enantioselective oxidative coupling of 2-naphthol itself was achieved by the aerobic oxidative reaction catalyzed by the photoactivated chiral ruthenium(II)-salen complex 73. 2 it reported that the (/ ,/ )-chloronitrosyl(salen)ruthenium complex [(/ ,/ )-(NO)Ru(II)salen complex] effectively catalyzed the aerobic oxidation of racemic secondary alcohols in a kinetic resolution manner under visible-light irradiation. The reaction mechanism is not fully understood although the electron transfer process should be involved. The solution of 2-naphthol was stirred in air under irradiation by a halogen lamp at 25°C for 24 h to afford BINOL 66 as the sole product. The screening of various chiral diamines and binaphthyl chirality revealed that the binaphthyl unit influences the enantioselection in this coupling reaction. The combination of (/f,f )-cyclohexanediamine and the (R)-binaphthyl unit was found to construct the most matched hgand to obtain the optically active BINOL 66 in 65% ee. 

On reaction with sodium sulfide in DMF, easily accessible racemic 2,2 -bis(bromomethyl)-l,l -binaphthyl 168 afforded dihydrothiepine 23 in 99% yield (Scheme 26) <1994JOC1326>. The racemic thiepine 23 was resolved by liquid chromatography on triacetylcellulose on a preparative scale to give (R)-(—)-23 (90% yield, 97% ee) and (. )-(+)-23 (83% yield, 100% ee) (Section 13.03.4.2). Alternatively, reaction of diamine ( 5)-(—)-198, which is derived from an enantiomer (.) )-(+)-197, and methyl iodide in MeCN and subsequent reaction with Na2S-9H20 in DMF gave ( S)-(+)-23 in 35% yield. 

The quantum yields decreases by changing from planar naphtholes to the perpendicular binaphthole independent on the absence or presence of pyridine [162], Also, in the case of optical active l,T-binaphthyl-2,2 -diamine (BNA) compared with A-phenyl-p-naphthylamine (PNA), the quantum yield of electron transfer is for BNA by a factor of 0.5 lower due to the perpendicular structure [161]. A possible explanation is that the approach of the perpendicular donors BN(OH)2 and BNA to the almost spherical fullerenes is hindered, while the planar 2-NOH and PNA more easily contact with the fullerenes [161,162], The quantum yields of C70 in the absence of pyridine are slightly higher than those of C6o suggesting a slightly stronger acceptor ability of C70 [162],... 

The Shi and Crabtree groups have found that iridium and rhodium complexes derived from BINAM (l,T-binaphthyl-2,2 -diamine) are also capable of the transformation. While Shi s Rh catalyst 37 [81] gave similar results to those reported by Gade, Crabtree s Ir catalyst 38 [82] was less effective, providing optical induction of only 60%. 

Vinylogous Mukaiyama-Michael additions of 2-trimethylsilyloxyfuran to 3-alkenoyl-2-oxazolidinones to provide 7-butenolides were shown to be /7-selective. The reaction could be rendered enantioselective in the presence of a (T symmetric copper-bisoxazoline complex <1997T17015, 1997SL568> or a l,T-binaphthyl-2,2 -diamine-nickel(ii) complex as catalyst, as depicted in Equation (16) <2004CC1414>. 

Note The axial chirality of the 1,T-binaphthyl scaffold is induced by the central chirality of the carbene unit [83,84]. This simplifies the issue of chirality from a synthetic point of view as the centrally chiral diamine is easier to purify than the axially chiral 1,1 -binaph-thyl scaffold that would otherwise be required. 

The hydroxy-binaphthyl functionalised saturated imidazolium salt is readily available from 1-amino-I -hydroxy-binaphthyl in a reaction with a ( oc-protected mesitylamine aldehyde [86] (see Figure 4.24). The resulting Schiff base is reduced to the diamine by Na(OAc)3BH. Subsequent deprotection and ring closure reaction with triethyl orthoformate yields the corresponding hydroxy-binaphthyl functionalised saturated imidazolium salt. Reaction with silver(I) carbonate and subsequent carbene transfer to the ruthenium(II) precursor yields the asymmetric olefin metathesis precatalyst. 

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