P-tol-BINAP

PMHS (1.1 eq), CuCl/NaOBu-t, (S)-p-Tol-BINAP (10 mol%), MeC6H5, temp then TBAF... 

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

The reaction is quite sensitive to the chiral ligand used. Diphosphines with an axially disymmetric biaryl moiety in the backbone give the best results. The effectiveness of p-Tol-BINAP as ligand, for example, is similar to that of BINAP. The related atropisomeric ligand BIPHEMP can also be used [9]. Among chiral aliphatic diphosphines tested, CyDIOP, which only differs from DIOP in the type of P-substituents, also gives satisfactory results. 

Another Ru(BINAP)-catalyzed asymmetric hydrogenation that has been performed at manufacturing scale involves the reduction of a functionalized ketone. The reduction of hydroxyacetone catalyzed by [NH2Et2]+[ RuCl(p-tol-BINAP) 2 (li-CI)3 (39) proceeds in 94% ee (Scheme 12.11).46 The chiral diol (40) is incorporated into the synthesis of levofloxacin (41), a quinolinecarboxylic acid that exhibits marked antibacterial activity. Current production of 40 is 40 tons per year by Takasago International Corp.46... 

Jorgensen et al. reported that C2-symmetric bis(oxazoline)-copper(II) complex 25 also acts as chiral Lewis acid catalyst for a reaction of allylic stannane with ethyl glyoxylate [37]. Meanwhile, p-Tol-BINAP-CuCl complex 26 was shown to be a promising chiral catalyst for a catalytic enantioselective allylation of ketones with allyltrimethoxysilane under the influence of the TBAT catalyst [38]. Evans and coworkers have developed (S,S)-Ph-pybox-Sc(OTf)3 complex 27 as a new chiral Lewis acid catalyst and shown that this scandium catalyst promotes enantioselective addition reactions of allenyltrimethylsilanes to ethyl glyoxylate [39]. But, when the silicon substituents become bulkier, nonracemic dihydrofurans are predominantly obtained as products of [3+2] cycloaddition. 

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