Synthesis and Characterization of β‐Diketiminate Aluminum Compounds and Their Use in the Ring‐Opening Polymerization of ε‐Caprolactone

Four aluminum alkyl compounds, [CH{(CH₃)CN‐2,4,6‐MeC₆H₂}₂AlMe₂] ( 1 ), [CH{(CH₃)CN‐2,4,6‐MeC₆H₂}₂AlEt₂] ( 2 ), [CH{(CH₃)CN‐2‐iPrC₆H₄}₂AlMe₂] ( 3 ), and [CH{(CH₃)CN‐2‐iPrC₆H₄}₂AlEt₂] ( 4 ), bearing β‐diketiminate ligands [CH{(Me)CN‐2,4,6‐MeC₆H₂}]₂ (L¹H) and [CH{(Me)CN‐2‐ⁱPrC₆H₄}]₂ (L²H) were obtained from the reactions of trimethylaluminum, triethylaluminum with the corresponding β‐diketiminate, respectively. All compounds were characterized by ¹H NMR and ¹³C NMR spectroscopy, single‐crystal X‐ray structural analysis, and elemental analysis. Compounds 1 – 4 were found to catalyze the ring‐opening polymerization (ROP) of ε‐caprolactone (ε‐CL) with good activity.     

Synthesis of ferrocene‐containing N‐aryloxo β‐ketoiminate lanthanide complexes and polymerization of ε‐caprolactone

The synthesis, characterization and ε‐caprolactone polymerization behavior of lanthanide amido complexes stabilized by ferrocene‐containing N‐aryloxo functionalized β‐ketoiminate ligand FcCOCH₂C(Me)N(2‐HO‐5‐Bu^t‐C₆H₃) (LH₂, Fc = ferrocenyl) are described. The lanthanide amido complexes [LLnN(SiMe₃)₂(THF)]₂ [Ln = Nd ( 1 ), Sm ( 2 ), Yb ( 3 ), Y ( 4 )] were synthesized in good yields by the amine elimination reactions of LH₂ with Ln[N(SiMe₃)₂]₃(µ‐Cl)Li(THF)₃ in a 1:1 molar ratio in THF. These complexes were characterized by IR spectroscopy and elemental analysis, and ¹H NMR spectroscopy was added for the analysis of complex 4 . The definitive molecular structures of complexes 1 and 3 were determined by X‐ray diffraction studies. Complexes 1 – 4 can initiate the ring‐opening polymerization of ε‐caprolactone with moderate activity. Copyright © 2011 John Wiley & Sons, Ltd.     

Synthesis and Characterization of β‐Diketiminate Zinc Complexes

The monomeric β‐diketiminate zinc complex (Mes)NacNacZnMe 1 (MesNacNac = {[2,6‐(2,4,6‐Me₃‐C₆H₂)N(Me)C)]₂CH}) was obtained in almost quantitative yield from the reaction of ZnMe₂ with (Mes)NacNacH. Reaction of 1 with either Me₃NHCl or a solution of HCl in Et₂O yielded (Mes)NacNacZnCl 2 , whereas (Mes)NacNacZnI 3 was obtained from the reaction of 1 with I₂. 1 – 3 were characterized by elemental analyses, mass and multinuclear (¹H, ¹³C{¹H}) NMR spectroscopy, 3·THF also by single crystal X‐ray analysis.     

On the Reactivity of Platina‐β‐diketones – Synthesis and Characterization of Acylplatinum(II) Complexes

The platina‐β‐diketones [Pt₂{(COR)₂H}₂(μ‐Cl)₂] ( 1 , R = Me a , Et b ) react with phosphines L in a molar ratio of 1 : 4 through cleavage of acetaldehyde to give acylplatinum(II) complexes trans‐[Pt(COR)Cl(L)₂] ( 2 ) (R/L = Me/P(p‐FC₆H₄)₃ a , Me/P(p‐CH₂=CHC₆H₄)Ph₂ b , Me/P(n‐Bu)₃ c , Et/P(p‐MeOC₆H₄)₃ d ). 1 a reacts with Ph₂As(CH₂)₂PPh₂ (dadpe) in a molar ratio of 1 : 2 through cleavage of acetaldehyde yielding [Pt(COMe)Cl(dadpe)] ( 3 a ) (configuration index: SP‐4‐4) and [Pt(COMe)Cl(dadpe)] (configuration index: SP‐4‐2) ( 3 b ) in a ratio of about 9 : 1. All acyl complexes were characterized by ¹H, ¹³C and ³¹P NMR spectroscopy. The molecular structures of 2 a and 3 a were determined by single‐crystal X‐ray diffraction. The geometries at the platinum centers are close to square planar. In both complexes the plane of the acyl ligand is nearly perpendicular to the plane of the complex (88(2)° 2 a , 81.2(5)° 3 a ).     

Tetrylenes chelated by bifunctional β‐diketiminate ligand: structure and possible applications

The synthesis and structure of heteroleptic tetrylenes containing bifunctional β‐diketiminate ligand are reported. Compounds were prepared via a protolytic reaction of free β‐diketimine {N‐[(2‐MeO)C₆H₅]}N═C(Me)CH═C(Me)N(H){N′‐[(2‐MeO)C₆H₅]} (L^COH) and {N‐[(2‐MeO)C₆H₅]}N?CHCH?CHN(H){N′‐[(2‐MeO)C₆H₅]} (L^HOH), respectively, with corresponding bis(amide) – M[N(SiMe₃)₂]₂ (M = Ge, Sn, Pb) – in equimolar ratio or via the salt elimination route from lithium precursors generated from L^HOH/L^COH species and slight excess of SnCl₂ or GeCl₂.dioxane complex. Only heteroleptic complexes were obtained by the mentioned methods. Products were characterized by multinuclear NMR spectroscopy techniques and structures of four of them have been determined by X‐ray diffraction methods. Complexes L^HOGeCl and L^COSnN(SiMe₃)₂ crystallize as monomers with the three‐coordinated metal centres by one chloro or amido ligand and one bidentate β‐diketiminato unit, in contrast to the structure of L^COSnCl, which reveals a dimeric character and compound L^COPbN(SiMe₃)₂, where the central atom of lead is five‐coordinated by methoxy groups of the ligand. Complex L^COSnN(SiMe₃)₂ was tested as a catalyst for polymerization of various epoxides_. Copyright © 2014 John Wiley & Sons, Ltd.     

A Novel,One‐Pot Four‐Component Route to 2′‐Thioxo‐2′,3′‐dihydrospiro[indole‐3,6′‐[1,3]thiazin]‐2‐one Derivatives

An efficient route to 2′,3′‐dihydro‐2′‐thioxospiro[indole‐3,6′‐[1,3]thiazin]‐2(1H)‐one derivatives is described. It involves the reaction of isatine, 1‐phenyl‐2‐(1,1,1‐triphenyl‐λ⁵‐phosphanylidene)ethan‐1‐one, and different amines in the presence of CS₂ in dry MeOH at reflux (Scheme 1). The alkyl carbamodithioate, which results from the addition of the amine to CS₂, is added to the α,β‐unsaturated ketone, resulting from the reaction between 1‐phenyl‐2‐(1,1,1‐triphenyl‐λ⁵‐phosphanylidene)ethan‐1‐one and isatine, to produce the 3′‐alkyl‐2′,3′‐dihydro‐4′‐phenyl‐2′‐thioxospiro[indole‐3,6′‐[1,3]thiazin]‐2(1H)‐one derivatives in excellent yields (Scheme 2). Their structures were corroborated spectroscopically (IR, ¹H‐ and ¹³C‐NMR, and EI‐MS) and by elemental analyses.     

Synthesis and Structural Characterization of ZnII α‐Diimine Complexes with Chloride and Thiocyanate Co‐Ligands

The preparation and spectroscopic and structural characterization of three Zn^II complexes with bis[N‐(2,6‐dimethylphenyl)imine]acenaphthene, L¹, and with bis[N‐(2‐ethylphenyl)imine]acenaphthene, L², are decribed herein. Two of the complexes were prepared from ZnCl₂ and the third from Zn(NCS)₂. One‐pot reaction techniques were used, leading to high yields. The complexes were characterized by microanalysis, IR and ¹H NMR spectroscopy, and single‐crystal X‐ray diffraction. The structures of the complexes are significantly different, with the chloride‐containing species forming distorted tetrahedra around the metal, whereas its thiocyanate analog is dimeric, with each metal at the center of a distorted square pyramid, with bridging and terminal [SCN]^– ligands.     

Synthesis,characterization and release profiles of nanoparticles self‐assembled from poly (PEGMA‐co‐MMA‐co‐acryloyl‐β‐CD) copolymers

A novel amphiphilic copolymer was synthesized from poly (ethylene glycol) methyl ether methacrylate (PEGMA950), methyl methacrylate (MMA) and acryloyl‐β‐cyclodextrin (acryloyl‐β‐CD) using the composites of (NH₄)₂S₂O₈/NaHSO₃ as the oxidation–reduction initiators. The successful fabrication of poly(PEGMA‐co‐MMA‐co‐acryloyl‐β‐CD) copolymers was confirmed by Fourier transform infrared spectrometer (FTIR), ¹H‐nuclear magnetic resonance (¹H NMR) spectra. The amphiphilic copolymer could self‐assemble into nanoparticles (NPs), and their morphology and particle size distribution were characterized with transmission electron microscopy (TEM), atomic force microscope (AFM) and dynamic light scattering (DLS) methods. Ibuprofen (IBU) was encapsulated in the novel NPs, and the release profiles of IBU were investigated. FTIR and ¹H NMR spectra illustrated that the poly(PEGMA‐co‐MMA‐co‐acryloyl‐β‐CD) copolymers were synthesized without any residual monomers and initiators. TEM and AFM photographs suggested that the obtained NPs were spherical, and the DLS results indicated that the diameter of blank NPs was 157.3 ± 32.7 nm. The IBU release profile showed that the IBU‐loaded NPs had certain pH responsibility. Copyright © 2014 John Wiley & Sons, Ltd.     

Synthesis and Structure of Low‐valent η4‐Cinnamaldehyde Cobalt Complexes

Three η⁴‐(C=C–C=O) coordination cobalt(I) complexes 1 – 3 were synthesized by the reactions of cinnamaldehyde, p‐fluorocinnamaldehyde, and p‐chlorocinnamaldehyde with CoMe(PMe₃)₄. Complex 4 as η²‐(C=C) coordination was prepared by the reaction of chalcone with Co(PMe₃)₄. The structures of complexes 1 – 4 were confirmed by single‐crystal X‐ray diffraction. Although the reactions didn't undergo C–H bond activation and decarbonylation, the formation of complexes 1 – 4 deepens our understanding of the reactions between α,β‐unsaturated aldehyde or ketone with low‐valent central cobalt atom.     

Stereoselective Preparation of 3‐Amino‐2‐fluoro Carboxylic Acid Derivatives,and Their Incorporation in Tetrahydropyrimidin‐4(1H)‐ones,and in Open‐Chain and Cyclic β‐Peptides

The preparation of (2S,3S)‐ and (2R,3S)‐2‐fluoro and of (3S)‐2,2‐difluoro‐3‐amino carboxylic acid derivatives, 1 – 3 , from alanine, valine, leucine, threonine, and β³h‐alanine (Schemes 1 and 2, Table) is described. The stereochemical course of (diethylamino)sulfur trifluoride (DAST) reactions with N,N‐dibenzyl‐2‐amino‐3‐hydroxy and 3‐amino‐2‐hydroxy carboxylic acid esters is discussed (Fig. 1). The fluoro‐β‐amino acid residues have been incorporated into pyrimidinones ( 11 – 13 ; Fig. 2) and into cyclic β‐tri‐ and β‐tetrapeptides 17 – 19 and 21 – 23 (Scheme 3) with rigid skeletons, so that reliable structural data (bond lengths, bond angles, and Karplus parameters) can be obtained. β‐Hexapeptides Boc[(2S)‐β³hXaa(αF)]₆OBn and Boc[β³hXaa(α,αF₂)]₆‐OBn, 24 – 26 , with the side chains of Ala, Val, and Leu, have been synthesized (Scheme 4), and their CD spectra (Fig. 3) are discussed. Most compounds and many intermediates are fully characterized by IR‐ and ¹H‐, ¹³C‐ and ¹⁹F‐NMR spectroscopy, by MS spectrometry, and by elemental analyses, [α]_D and melting‐point values.     

Synthesis and Structures of Gallium‐β‐Diketiminate Complexes: Isolation of a Dinuclear Gallium(II) Complex

The sterically demanding β‐diketiminate ligand L^dmp [L^dmp = HC{(CMe)N(dmp)}₂, dmp = C₆H₃‐2,6‐Me₂] was used to stabilize various gallium complexes in the formal oxidation states +II and +III. The reaction of in situ generated [L^dmpLi] with gallium chloride affords [L^dmpGaCl₂] ( 1 ), which was used as starting complex to synthesize a variety of gallium(III) compounds [L^dmpGaX₂] [X = F ( 2 ), I ( 3 ), H ( 4 ), and Me ( 5 )]. Synthesis of the dinuclear complex [L^dmpGaI]₂ ( 6 ), with gallium in the formal oxidation state +II was accomplished by converting “GaI” with in situ generated [L^dmpLi] in toluene. All compounds were characterized by elemental analyses, NMR spectroscopy, LIFDI‐TOF‐MS, and single‐crystal X‐ray diffraction. Additionally DFT calculations were performed for analysis of the bonding in 6 .     

Microwave‐Assisted Synthesis of β‐Lactams and Cyclo‐β‐dipeptides

Different cyclo‐β‐dipeptides were prepared from corresponding N‐substituted β‐alanine derivatives under mild conditions using PhPOCl₂ as activating agent in benzene and Et₃N as base. To evaluate β³‐substituent influence, the amino acids 7 – 26 were synthesized, and a β‐lactam formation reaction was carried out instead of cyclo‐β‐dipeptide formation. The crystal structures of three derivatives of cyclo‐β‐peptides and one β‐lactam are presented.     

1H NMR studies of binary and ternary dapsone supramolecular complexes with different drug carriers: EPC liposome,SBE‐β‐CD and β‐CD

Binary and ternary systems composed of dapsone, sulfobutylether‐β‐cyclodextrin (SBE‐β‐CD), β‐CD and egg phosphatidylcholine (EPC) were evaluated using 1D ROESY, saturation transfer difference NMR and diffusion experiments (DOSY) revealing the binary complexes Dap/β‐CD (K_a 1396 l mol^?1), Dap/SBE‐β‐CD (K_a 246 l mol^?1), Dap/EPC (K_a 84 l mol^?1) and the ternary complex Dap/β‐CD/EPC (K_a 18 l mol^?1) in which dapsone is more soluble. Copyright © 2014 John Wiley & Sons, Ltd.     

Syntheses,and Crystal Structures of Indium Complexes with η2‐Piperidinyldithiocarbamate and η2‐Pyridine‐2‐Thionate Containing Ligands: Structures of [In(η2‐S2CNC5H10)3] and [In(η2‐pyS)3]

The η²‐thio‐indium complexes [In(η²‐thio)₃] (thio = S₂CNC₅H₁₀, 2 ; SNC₄H₄, (pyridine‐2‐thionate, pyS, 3 ) and [In(η²‐pyS)₂(η²‐acac)], 4 , (acac: acetylacetonate) are prepared by reacting the tris(η²‐acac)indium complex [In(η²‐acac)₃], 1 with HS₂CNC₅H₁₀, pySH, and pySH with ratios of 1:3, 1:3, and 1:2 in dichloromethane at room temperature, respectively. All of these complexes are identified by spectroscopic methods and complexes 2 and 3 are determined by single‐crystal X‐ray diffraction. Crystal data for 2 : space group, C2/c with a = 13.5489(8) Å, b = 12.1821(7) Å, c = 16.0893(10) Å, β = 101.654(1)°, V = 2600.9(3) ų, and Z = 4. The structure was refined to R = 0.033 and Rw = 0.086; Crystal data for 3 : space group, P2₁ with a = 8.8064 (6) Å, b = 11.7047 (8) Å, c = 9.4046 (7) Å, β = 114.78 (1)°, V = 880.13(11) ų, and Z = 2. The structure was refined to R = 0.030 and Rw = 0.061. The geometry around the metal atom of the two complexes is a trigonal prismatic coordination. The piperidinyldithiocarbamate and pyridine‐2‐thionate ligands, respectively, coordinate to the indium metal center through the two sulfur atoms and one sulfur and one nitrogen atoms, respectively. The short C‐N bond length in the range of 1.322(4)–1.381(6) Å in 2 and C‐S bond length in the range of 1.715(2)–1.753(6) Å in 2 and 3 , respectively, indicate considerable partial double bond character.     

Synthesis and High‐Resolution NMR Structure of a β3‐Octapeptide with and without a Tether Introduced by Olefin Metathesis

Bridging between (i)‐ and (i+3)‐positions in a β³‐peptide with a tether of appropriate length is expected to prevent the corresponding 3₁₄‐helix from unfolding (Fig. 1). The β³‐peptide H‐β³hVal‐β³hLys‐β³hSer(All)‐β³hPhe‐β³hGlu‐β³hSer(All)‐β³hTyr‐β³hIle‐OH ( 1 ; with allylated βhSer residues in 3‐ and 6‐position), and three tethered β‐peptides 2 – 4 (related to 1 through ring‐closing metathesis) have been synthesized (solid‐phase coupling, Fmoc strategy, on chlorotrityl resin; Scheme). A comparative CD analysis of the tethered β‐peptide 4 and its non‐tethered analogue 1 suggests that helical propensity is significantly enhanced (threefold CD intensity) by a (CH₂)₄ linker between the β³hSer side chains (Fig. 2). This conclusion is based on the premise that the intensity of the negative Cotton effect near 215 nm in the CD spectra of β³‐peptides represents a measure of ‘helical content’. An NMR analysis in CD₃OH of the two β³‐octapeptide derivatives without (i.e., 1 ) and with tether (i.e., 4 ; Tables 1–6, and Figs. 4 and 5) provided structures of a degree of precision (by including the complete set of side chain–side chain and side chain–backbone NOEs) which is unrivaled in β‐peptide NMR‐solution‐structure determination. Comparison of the two structures (Fig. 5) reveals small differences in side‐chain arrangements (separate bundles of the ten lowest‐energy structures of 1 and 4 , Fig. 5, A and B ) with little deviation between the two backbones (superposition of all structures of 1 and 4 , Fig. 5, C ). Thus, the incorporation of a CH₂? O? (CH₂)₄? O? CH₂ linker between the backbone of the β³‐amino acids in 3‐ and 6‐position (as in 4 ) does accurately constrain the peptide into a 3₁₄‐helix. The NMR analysis, however, does not suggest an increase in the population of a 3₁₄‐helical backbone conformation by this linkage. Possible reasons for the discrepancy between the conclusion from the CD spectra and from the NMR analysis are discussed.     

Synthesis of highly branched polyethylene using para‐phenyl‐substituted α‐diimine nickel catalysts

A series of para‐phenyl‐substituted α‐diimine nickel complexes, [(2,6‐R₂‐4‐PhC₆H₂N═C(Me))₂]NiBr₂ (R = ⁱPr ( 1 ); R = Et ( 2 ); R = Me ( 3 ); R = H ( 4 )), were synthesized and characterized. These complexes with systematically varied ligand sterics were used as precatalysts for ethylene polymerization in combination with methylaluminoxane. The results indicated the possibility of catalytic activity, molecular weight and polymer microstructure control through catalyst structures and polymerization temperature. Interestingly, it is possible to tune the catalytic activities ((0.30–2.56) × 10⁶ g (mol Ni·h)^?1), polymer molecular weights (M_n = (2.1–28.6) × 10⁴ g mol^?1) and branching densities (71–143/1000 C) over a very wide range. The polyethylene branching densities decreased with increasing bulkiness of ligand and decreasing polymerization temperature. Specifically, methyl‐substituted complex 3 showed high activities and produced highly branched amorphous polyethylene (up to 143 branches per 1000 C).     

On the reactivity of platina‐β‐diketones: a straightforward synthesis of trans‐acetylchlorobis(phosphine)platinum(II) complexes and their reactivity

The platina‐β‐diketone [Pt₂{(COMe)₂H}₂(µ‐Cl)₂] ( 1 ) was found to react with monodentate phosphines to yield acetyl(chloro)platinum(II) complexes trans‐[Pt(COMe)Cl(PR₃)₂] (PR₃ = PPh₃, 2a ; P(4‐FC₆H₄)₃, 2b ; PMePh₂, 2c ; PMe₂Ph, 2d ; P(n‐Bu)₃, 2e ; P(o‐tol)₃, 2f ; P(m‐tol)₃, 2g ; P(p‐tol)₃, 2h ). In the reaction with P(o‐tol)₃ the methyl(carbonyl)platinum(II) complex [Pt(Me)Cl(CO){P(o‐tol)₃}] ( 3a ) was found to be an intermediate. On the other hand, treating 1 with P(C₆F₅)₃ led to the formation of [Pt(Me)Cl(CO){P(C₆F₅)₃}] ( 3b ), even in excess of the phosphine. Phosphine ligands with a lower donor capability in complexes 2 and the arsine ligand in trans‐[Pt(COMe)Cl(AsPh₃)₂] ( 2i ) proved to be subject to substitution by stronger donating phosphine ligands, thus forming complexes trans‐[Pt(COMe)Cl(L)L′] (L/L′ = AsPh₃/PPh₃, 4a ; PPh₃/P(n‐Bu)₃, 4b ) and cis‐[Pt(COMe)Cl(dppe)] ( 4c ). Furthermore, in boiling benzene, complexes 2a – 2c and 2i underwent decarbonylation yielding quantitatively methyl(chloro)platinum(II) complexes trans‐[Pt(Me)Cl(L)₂] (L = PPh₃, 5a ; P(4‐FC₆H₄)₃, 5b ; PMePh₂, 5c ; AsPh₃, 5d ). The identities of all complexes were confirmed by ¹H, ¹³C and ³¹P NMR spectroscopy. Single‐crystal X‐ray diffraction analyses of 2a ·2CHCl₃, 2f and 5b showed that the platinum atom is square‐planar coordinated by two phosphine ligands (PPh₃, 2a ; P(o‐tol)₃, 2f ; P(4F‐C₆H₄)₃, 5b ) in mutual trans position as well as by an acetyl ligand ( 2a, 2f ) and a methyl ligand ( 5b ), respectively, trans to a chloro ligand. Single‐crystal X‐ray diffraction analysis of 3b exhibited a square‐planar platinum complex with the two π‐acceptor ligands CO and P(C₆F₅)₃ in mutual cis position (configuration index: SP‐4‐3). Copyright © 2005 John Wiley & Sons, Ltd.     

Pinacol Rearrangement of 3,4‐Dihydro‐3,4‐dihydroxyquinolin‐2(1H)‐ones: An Alternative Pathway to Viridicatin Alkaloids and Their Analogs

3‐Alkyl/aryl‐3‐hydroxyquinoline‐2,4‐diones were reduced with NaBH₄ to give cis‐3‐alkyl/aryl‐3,4‐dihydro‐3,4‐dihydroxyquinolin‐2(1H)‐ones. These compounds were subjected to pinacol rearrangement by treatment with concentrated H₂SO₄, resulting in 4‐alkyl/aryl‐3‐hydroxyquinolin‐2(1H)‐ones. When a benzyl (Bn) group was present in position 3 of the starting compound, its elimination occurred during the rearrangement, and the corresponding 3‐hydroxyquinolin‐2(1H)‐one was formed. The reaction mechanisms are discussed for all transformations. All compounds were characterized by IR, ¹H‐ and ¹³C‐NMR spectroscopy, as well as mass spectrometry.     

Synthesis of β‐Hydroxy α‐Sulfanyl Esters by Using Nanocrystalline Magnesium Oxide

Aldol‐type reaction between electron deficient aldehydes and sulfonium salts to afford the corresponding β‐hydroxy α‐sulfanyl esters in moderate‐to‐good yields by using nanocrystalline MgO is described. The sulfanyl group is a useful group for further transformations in organic synthesis. Low R_f‐value isomer is anti‐configured as revealed by X‐ray diffraction study and consistent with the assignment of ¹H‐NMR spectrum.     

Fluorescence Sensing and Selective Binding of a Novel 4,4′‐Sulfonyldianiline‐Bridged Bis(β‐cyclodextrin) for Bile Salts

A novel 4,4′‐sulfonyldianiline‐bridged bis(β‐cyclodextrin (CD)) 2 was synthesized, and its complex stability constants (K_s) for the 1 : 1 inclusion complexation with bile salts, i.e., cholate (CA), deoxycholate (DCA), glycocholate (GCA), and taurocholate (TCA) have been determined in phosphate buffer (pH 7.2) at 25° by fluorescence spectroscopy. The result indicated that 2 can act as efficient fluorescent sensor and display remarkable fluorescence enhancement upon addition of optically inert bile salts. Structures of the inclusion complexes between bile salts and 2 were elucidated by 2D‐NMR experiments, indicating that the anionic tail group and the D ring of bile salts penetrate into one CD cavity of 2 from the wide opening deeply, while the phenyl moiety of the CD linker is partially self‐included in the other CD cavity to form a host–linker–guest binding mode. As compared with native β‐CD 1 upon complexation with bile salts, bis(β‐CD) 2 enhances the binding ability and molecular selectivity. Typically, 2 gives the highest K_s value of 26200 M ^?1 for the complexation with CA, which may be ascribed to the simultaneous contributions of hydrophobic, H‐bond, and electrostatic interactions. These phenomena are discussed from the viewpoints of multiple recognition and induce‐fit interactions between host and guest.