Binaphthyl-derived amine, chiral

In 2005, Wang and coworkers reported a new bifunctional binaphthyl-derived amine thiourea 16 as an efficient organocatalyst for the Morita-Baylis-Hillman reaction of cyclohexenone with aliphatic, aromatic and sterically hindered aldehydes. The design of the catalyst follows Takemoto s design of a bifunctional motif. This catalytic protocol provided access to useful chiral allylic alcohol building blocks in high yields and high enan-tioselectivities (Scheme 19.21). 

The design and synthesis of a new class of chiral secondary amines represents a powerful approach to greatly expanding the scope of asymmetric catalysis based on the generation of enamine and iminium ions as a reactive intermediate. Maruoka has made significant contributions to this field of research through the development of a series of binaphthyl-derived, axially chiral C2-symmetric secondary amines of type 17 and 18 (Figure 7.3). 

List was the first to explore this possibility, examining the Hantzsch ester mediated reduction of a,P-unsaturated aldehydes [209], Using 20 mol% of the binaphthyl derived phosphonate salt of morpholine (153) in dioxane at 50 °C, a series of P-aryl a,P-unsaturated aldehydes underwent transfer hydrogenation with Hantzsch ester 154 with excellent levels of absolute stereocontrol (96-98% ee) (Scheme 63). The method was also applied to the aliphatic substrates ( )-citral and famesal to give the mono-reduced products in 90% and 92% ee, respectively. Significantly, in line with many of the chiral secondary amine catalysed transformations described above the reactions follow a simple and practical procedure without the need for exclusion of moisture and air. 

Being inspired by Maruoka s results with the C2-symmetric binaphthyl-derived quaternary ammonium salt [21], Lygo and colleagues designed a quaternary ammonium salt 23, comprising conformationally flexible biphenyl units and commercially available chiral secondary amines [22], A library of 40 quaternary ammonium salt was synthesized and evaluated for their catalytic efficiency in the asymmetric alkylation of... 

Binaphthyl derivatives. Muratore and co-workers have described the chiral Bronsted acids (122-127) that catalyzed dehydrative condensation of enol lactones (119) and amines, such as tryptamine (120), to give (121) (Scheme 30). ... 

Binaphthyl derivatives. Cooperative catalysis by [Pd(dba)2] and the chiral phosphoric acid (204) in combination with the phos-phoramidite ligand (205) has been applied for efficient enantioselective amination of racemic allylic alcohols (202) with a variety of functionalised amines (203) (Scheme 54). ... 

Maruoka also uhlized 3,3 -modified binaphthyl-derived chiral primary amine 21, in combination with trifluoromethanesulfonic acid (TfOH), as a catalyst for the Diels-Alder reachon of a-substituted a,P-unsaturated aldehydes with cyclopenta-diene, which afforded the corresponding cycloadducts possessing an all-carbon quaternary stereocenter with good to high stereoselectivity (Scheme 7.34) [58],... 

Muller has explored enantioselective C-H insertion using optically active rhodium complexes, NsN=IPh as the oxidant, and indane 7 as a test substrate (Scheme 17.8) [35]. Chiral rhodium catalysts have been described by several groups and enjoy extensive application for asymmetric reactions with diazoalkanes ]46—48]. In C-H amination experiments, Pirrung s binaphthyl phosphate-derived rhodium system was found to afford the highest enantiomeric excess (31%) of the product sulfonamide 8 (20equiv indane 7, 71% yield). 

For enhancement of fluorescence, molecules with intramolecular fluorescence quenching of photoinduced electron transfer (PET) of lone pairs are used. When interacting with the target molecule, this quenching will be inhibited and therefore the fluorescence can be turned on. The l,T-binaphthyl macrocycles are most extensively applied for this method they provide multiple chiral functional groups as binding sites for analytes such as a-hydroxycarboxylic acids, amines and even amino acid derivatives [5] (Fig. 3, left). 

Other ligands giving >90% ee for the alkylation or amination of 19 have been reported but will not be described in detail. They include derivatives of 3 [36], ferrocene-based ligands [54-57], l.l -binaphthyl-based ligands [58-60], natural product-based ligands such as fenchone [61], cholesterol [62], or carbohydrates [63,64], chiral aryl chromium complexes [65,66], chiral sulfimides [67], newP,N-ligands [19,22,52,53,68-78], and others [79-82]. 

Related Reagents. The synthesis of chiral diazenedicarboxylates as potential chiral electrophilic aminating agents has received little attention. A series of chiral bomyl, isobomyl and menthyl diazenedicarboxylates has been reported and their reaction with achiral enolates of esters and N,N-dimethyl amides afforded a-hydrazino acid derivatives with little or no selectivity. Incorporation of a chiral azodicarboxamide unit into a chiral bridging binaphthyl moiety afforded a-hydrazino acid derivatives with high stereoselectivity in reactions with achiral oxazolidinone anions. ... 

In 2009, P-chiral phosphorus triamide ligands were applied in Ni-catalyzed asymmetric hydrovinylation of styrene with promising results, good yields (77%), and good enantioselectivity (up to 63% ee). Recently, phosphoramidite and P-stereogenic phosphorodiamidite ligands L17 and L18 derived from (Sj-2-phenylamino-2 -hydroxy-l,l -binaphthyl (7y-Ph-NOBIN) and bis(l-phenyl-ethyl)amine were synthesized and applied in asymmetric hydrovinylation of styrene, leading to almost perfect selectivity and enantioselectivity (up to 91% ee) (Scheme 9.5). ... 

Cation and solvent hydrogen bonding to the hydrophilic phosphate group of the anion BNPPA (l,l-binaphthyl-2-diyl phosphate) (71) leads to bilayers with an interior hydrophilic region and with hydrophobic binaphthyl groups on both exterior sides.A simple thiophosphate-based method for 2-alkylidenation of lactones has been described. Phosphorus-derived chiral auxiliaries for a-alkylation of secondary amines by anodic oxidation has been elaborated. lodotrimethyl-sUane, which is routinely used for the dealkylation of ethers and esters, may be used to iodinate allyl or benzyl diethyl phosphates. ... 

The aldolisation of cyclic ketones with benzaldehydes performed in water was carried out by using a novel bifunctional trara-cyclohexyldiamine-derived primary amine, which bore both central and axial chiral elements. The aldol products were isolated with excellent levels of diastereo- and enantioselectivities and high yields, as shown in Scheme 2.34. Moreover, the high efficiency of this binaphthyl catalyst could be extended to aliphatic ketones such as acetone, which led to the corresponding aldol adduct in 71% yield and 87% ee in similar conditions. 

Chiral crown ethers are synthetic macrocyclic polyethers and were first introduced as CSPs for LC by Cram and co-workers in the late 1970s. In their pioneer works, bis-(l,r-binaphthyl)-22-crown-6 was immobilized on silica gel [126] or polystyrene [127] to resolve a-amino acids and their derivatives. Since then, different chiral crown ether CSPs have been developed and successfully applied in the HPLC separation of enantiomers containing primary amine and secondary amine groups [20, 128-139]. Both dynamically coated [128, 129] and covalently bonded [130-132] chiral crown ether CSPs are commercially available. 

As a novel type of proline-based secondary amine, Du devised the chiral binaphthyl bis-sulfonamide 19 and demonstrated that it could act as an efficient catalyst for the asymmetric Michael addition of cyclohexanone to nitrostyrene, giving rise to the corresponding y-nitroketone derivative with high levels of diastereo- and enantioselectivity (Scheme 7.32) [56]. 

Not only derivatives from proline are able to catalyze this transformation but also binaphthyl-based chiral secondary amine 67 (5 mol%) has been applied in the a-aminoxylation of both aldehyde and ketone substrates [99]. 

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