•Two diphosphine-Pd organometallic polymers were successfully synthesized.•The polymer catalysts can catalyze the Suzuki-Miyaura coupling reactions.•The polymers were highly stable and showed no metal leaching in the reaction process.•Catalyst P2 could be recycled for at least six times without loss of its activity.Two diphosphines 1,4-bis(diphenylphosphino)benzene (M1) and 4,4′-bis(diphenylphosphino)-1,1′-biphenyl (M2) were synthesized by employing Grignard reaction. They were subsequently employed to coordinate with palladium chloride to construct main-chain diphosphine-Pd organometallic polymers P1 and P2, respectively. Both polymers were used as self-supported heterogeneous catalysts for Suzuki-Miyaura coupling reactions of various aryl halides and arylboronic acids at room temperature. A higher catalytic activity for P1 and P2 than their homogeneous counterpart were observed, and the activity of P2 is slightly higher than that of P1. Moreover, polymer P2 can be readily recovered and reused for further transformations at least six times without decrease in catalytic activity, while an obvious decline of activity for P1 was observed after the fourth run.Main-chain diphosphine-Pd Polymer was synthesized and used as an efficient heterogeneous palladium catalyst for Suzuki-Miyaura coupling reaction.Download full-size image

•The adamantane-based bis-NHC-palladium polymer was synthesized.•The polymer catalyst was employed to catalyze the Suzuki–Miyaura coupling reactions.•The coupling products were obtained in moderate to excellent yields.•Catalyst could be recycled for at least four times without loss of its activity.An adamantane-based bis-NHC-palladium polymer was synthesized and characterized by FT-IR, solid state 13C NMR, element analysis, TGA, XRD, SEM, TEM and N2 sorption. And then it was employed as heterogeneous palladium catalyst in the Suzuki–Miyaura coupling reactions of aryl halides and benzoboric acids, giving the products in moderate to excellent yields. Compared with the homogeneous catalyst such as Pd(OAc)2, Pd(PPh3)4 and PdCl2(dppf), our prepared polymer catalyst showed more catalytic activity in the coupling reaction. Furthermore, the polymer catalyst can be readily recovered and reused for further transformations at least four cycles without observing significant decrease in catalytic activity.

Titanium mediated asymmetric Mannich reactions using imidazolidin-2-thione as a chiral auxiliary proceeded in good yields and with high diastereoselectivity to afford the anti-products in the presence of PPh3 additive. A non-chelated transition state with the PPh3-bound titanium enolate was proposed to explain the stereochemistry of the product. Alcoholysis of the adducts with methanol cleaved the imidazolidin-2-thione auxiliary to give the methyl esters in good yields and with excellent ee values.(S)-5-Isopropyl-3-phenyl-2-thioxoimidazolidin-4-oneC12H14N2OS[α]D20 = −53.9 (c 1.00, CHCl3)Absolute configuration: (S)Source of chirality: l-valine(S)-5-Methyl-3-phenyl-2-thioxoimidazolidin-4-oneC10H10N2OS[α]D20 = −22.8 (c 1.00, CH2Cl2)Absolute configuration: (S)Source of chirality: l-alanine(S)-5-Benzyl-3-phenyl-2-thioxoimidazolidin-4-oneC16H14N2OS[α]D20 = −245.8 (c 0.16, CH2Cl2)Absolute configuration: (S)Source of chirality: l-phenylalanine(S)-5-((S)-sec-Butyl)-3-phenyl-2-thioxoimidazolidin-4-oneC13H16N2OS[α]D20 = −47.0 (c 0.14, CH2Cl2)Absolute configuration: (5S,1′S)Source of chirality: l-isoleucine(S)-5-(tert-Butyl)-3-phenyl-2-thioxoimidazolidin-4-oneC13H16N2OS[α]D20 = −390.5 (c 0.14, CH2Cl2)Absolute configuration: (S)Source of chirality: l-tertiary leucine(S)-4-Isopropyl-1-phenylimidazolidin-2-thioneC12H16N2S[α]D20 = −36.1 (c 1.00, CH2Cl2)Absolute configuration: (S)Source of chirality: 3-phenyl-2-thioxoimidazolidin-4-one(S)-4-Methyl-1-phenylimidazolidin-2-thioneC10H12N2S[α]D20 = −183.9 (c 0.16, CH2Cl2)Absolute configuration: (S)Source of chirality: 3-phenyl-2-thioxoimidazolidin-4-one(S)-4-Benzyl-1-phenylimidazolidin-2-thioneC16H16N2S[α]D20 = −127.6 (c 0.24, CH2Cl2)Absolute configuration: (S)Source of chirality: 3-phenyl-2-thioxoimidazolidin-4-one(S)-4-((S)-sec-Butyl)-1-phenylimidazolidin-2-thioneC13H18N2S[α]D20 = −70.8 (c 0.16, CH2Cl2)Absolute configuration: (4S,1′S)Source of chirality: 3-phenyl-2-thioxoimidazolidin-4-one(S)-4-(tert-Butyl)-1-phenylimidazolidin-2-thioneC13H18N2S[α]D20 = −189.4 (c 0.15, CH2Cl2)Absolute configuration: (S)Source of chirality: 3-phenyl-2-thioxoimidazolidin-4-one(S)-N-Propionyl-4-isopropyl-1-phenylimidazolidin-2-thioneC15H20N2OS[α]D20 = +98.9 (c 1.00, CHCl3)Absolute configuration: (S)Source of chirality: 1-phenylimidazolidin-2-thione(S)-N-Butyryl-4-isopropyl-1-phenylimidazolidin-2-thioneC16H22N2OS[α]D20 = +79.4 (c 0.17, CH2Cl2)Absolute configuration: (S)Source of chirality: 1-phenylimidazolidin-2-thione(S)-N-Valeryl-4-isopropyl-1-phenylimidazolidin-2-thioneC17H24N2OS[α]D20 = +92.2 (c 0.15, CH2Cl2)Absolute configuration: (S)Source of chirality: 1-phenylimidazolidin-2-thione(S)-N-Isovaleryl-4-isopropyl-1-phenylimidazolidin-2-thioneC17H24N2OS[α]D20 = +57.9 (c 0.19, CH2Cl2)Absolute configuration: (S)Source of chirality: 1-phenylimidazolidin-2-thione(S)-N-Hexanoyl-4-isopropyl-1-phenylimidazolidin-2-thioneC18H26N2OS[α]D20 = +54.6 (c 0.20, CH2Cl2)Absolute configuration: (S)Source of chirality: 1-phenylimidazolidin-2-thione(S)-N-tert-Butylacetyl-4-isopropyl-1-phenylimidazolidin-2-thioneC18H26N2OS[α]D20 = +92.6 (c 0.17, CH2Cl2)Absolute configuration: (S)Source of chirality: 1-phenylimidazolidin-2-thione(S)-N-Phenylacetyl-4-isopropyl-1-phenylimidazolidin-2-thioneC20H22N2OS[α]D20 = +107.7 (c 0.22, CH2Cl2)Absolute configuration: (S)Source of chirality: 1-phenylimidazolidin-2-thione(S)-N-(3-Phenylpropionyl)-4-isopropyl-1-phenylimidazolidin-2-thioneC21H24N2OS[α]D20 = +87.5 (c 0.14, CH2Cl2)Absolute configuration: (S)Source of chirality: 1-phenylimidazolidin-2-thione(S)-N-Propionyl-4-methyl-1-phenylimidazolidin-2-thioneC13H16N2OS[α]D20 = +225.7 (c 0.11, CH2Cl2)Absolute configuration: (S)Source of chirality: 1-phenylimidazolidin-2-thione(S)-N-Propionyl-4-benzyl-1-phenylimidazolidin-2-thioneC19H20N2OS[α]D20 = +93.9 (c 0.43, CH2Cl2)Absolute configuration: (S)Source of chirality: 1-phenylimidazolidin-2-thione(S)-N-Propionyl-4-((S)-sec-butyl)-1-phenylimidazolidin-2-thioneC16H22N2OS[α]D20 = +91.3 (c 0.65, CH2Cl2)Absolute configuration: (4S,1′S)Source of chirality: 1-phenylimidazolidin-2-thione(S)-N-Propionyl-4-(tert-butyl)-1-phenylimidazolidin-2-thioneC16H22N2OS[α]D20 = +45.2 (c 0.56, CH2Cl2)Absolute configuration: (S)Source of chirality: 1-phenylimidazolidin-2-thione(5S,2′R,3′S)-5-Isopropyl-3-phenyl-1-[2′-methyl-3′-(p-methoxyphenylamino)-3′-phenyl-propionyl]imidazolidin-2-thioneC29H33N3O2S[α]D20 = +123.5 (c 0.28, CH2Cl2)Absolute configuration: (5S,2′R,3′S)Source of chirality: 1-phenylimidazolidin-2-thione induced Mannich reactions(5S,2′R,3′S)-5-Isopropyl-3-phenyl-1-[2′-methyl-3′-(p-methoxyphenylamino)-3′-(p-chloro-phenyl)-propionyl]imidazolidin-2-thioneC29H32ClN3O2S[α]D20 = +95.2 (c 0.14, CH2Cl2)Absolute configuration: (5S,2′R,3′S)Source of chirality: 1-phenylimidazolidin-2-thione induced Mannich reactions(5S,2′R,3′S)-5-Isopropyl-3-phenyl-1-[2′-methyl-3′-(p-methoxyphenylamino)-3′-(m-nitro-phenyl)-propionyl]imidazolidin-2-thioneC29H32N4O4S[α]D20 = +155.1 (c 0.13, CH2Cl2)Absolute configuration: (5S,2′R,3′S)Source of chirality: 1-phenylimidazolidin-2-thione induced Mannich reactions(5S,2′R,3′S)-5-Isopropyl-3-phenyl-1-[2′-methyl-3′-(p-methoxyphenylamino)-3′-(2″,3″-dimethoxyphenyl)-propionyl]imidazolidin-2-thioneC31H37N3O4S[α]D20 = +85.1 (c 0.58, CH2Cl2)Absolute configuration: (5S,2′R,3′S)Source of chirality: 1-phenylimidazolidin-2-thione induced Mannich reactions(5S,2′R,3′S)-5-Isopropyl-3-phenyl-1-[2′-methyl-3′-(p-methoxyphenylamino)-3′-(2″-furyl)-propionyl]imidazolidin-2-thioneC27H31N3O3S[α]D20 = +148.3 (c 0.15, CH2Cl2)Absolute configuration: (5S,2′R,3′S)Source of chirality: 1-phenylimidazolidin-2-thione induced Mannich reactions(5S,2′R,3′S)-5-Isopropyl-3-phenyl-1-[2′-methyl-3′-(p-methoxyphenylamino)-3′-(2″-thienyl)-propionyl]imidazolidin-2-thioneC27H31N3O2S2[α]D20 = +133.3 (c 0.40, CH2Cl2)Absolute configuration: (5S,2′R,3′S)Source of chirality: 1-phenylimidazolidin-2-thione induced Mannich reactions(5S,2′R,3′S)-5-Isopropyl-3-phenyl-1-[2′-methyl-3′-(p-methoxyphenylamino)-3′-phenyl-butyryl]imidazolidin-2-thioneC30H35N3O2S[α]D20 = +165.2 (c 0.11, CH2Cl2)Absolute configuration: (5S,2′R,3′S)Source of chirality: 1-phenylimidazolidin-2-thione induced Mannich reactions(5S,2′R,3′S)-5-Isopropyl-3-phenyl-1-[2′-methyl-3′-(p-methoxyphenylamino)-3′-phenyl-valeryl]imidazolidin-2-thioneC31H37N3O2S[α]D20 = +123.6 (c 0.24, CH2Cl2)Absolute configuration: (5S,2′R,3′S)Source of chirality: 1-phenylimidazolidin-2-thione induced Mannich reactions(5S,2′R,3′S)-5-Isopropyl-3-phenyl-1-[2′-methyl-3′-(p-methoxyphenylamino)-3′-phenyl-isovaleryl]imidazolidin-2-thioneC31H37N3O2S[α]D20 = +196.7 (c 0.21, CH2Cl2)Absolute configuration: (5S,2′R,3′S)Source of chirality: 1-phenylimidazolidin-2-thione induced Mannich reactions(5S,2′R,3′S)-5-Isopropyl-3-phenyl-1-[2′-methyl-3′-(p-methoxyphenylamino)-3′-phenyl-hexanoyl]imidazolidin-2-thioneC32H39N3O2S[α]D20 = +157.1 (c 0.13, CH2Cl2)Absolute configuration: (5S,2′R,3′S)Source of chirality: 1-phenylimidazolidin-2-thione induced Mannich reactions(5S,2′R,3′S)-5-Isopropyl-3-phenyl-1-[2′-methyl-3′-(p-methoxyphenylamino)-3′-phenyl-phenylacetyl]imidazolidin-2-thioneC34H35N3O2S[α]D20 = +138.3 (c 0.15, CH2Cl2)Absolute configuration: (5S,2′R,3′S)Source of chirality: 1-phenylimidazolidin-2-thione induced Mannich reactions(5S,2′R,3′S)-5-Isopropyl-3-phenyl-1-[2′-methyl-3′-(p-methoxyphenylamino)-3′-phenyl-(3-phenylpropionyl)]imidazolidin-2-thioneC35H37N3O2S[α]D20 = +112.1 (c 0.35, CH2Cl2)Absolute configuration: (5S,2′R,3′S)Source of chirality: 1-phenylimidazolidin-2-thione induced Mannich reactions(5S,2′R,3′S)-5-Methyl-3-phenyl-1-[2′-methyl-3′-(p-methoxyphenylamino)-3′-phenyl-propionyl]imidazolidin-2-thioneC27H29N3O2S[α]D20 = +136.2 (c 0.41, CH2Cl2)Absolute configuration: (5S,2′R,3′S)Source of chirality: 1-phenylimidazolidin-2-thione induced Mannich reactions(5S,2′R,3′S)-5-Benzyl-3-phenyl-1-[2′-methyl-3′-(p-methoxyphenylamino)-3′-phenyl-propionyl]imidazolidin-2-thioneC33H33N3O2S[α]D20 = +143.8 (c 0.50, CH2Cl2)Absolute configuration: (5S,2′R,3′S)Source of chirality: 1-phenylimidazolidin-2-thione induced Mannich reactions(5S,2′R,3′S)-5-((S)-sec-Butyl)-3-phenyl-1-[2′-methyl-3′-(p-methoxyphenylamino)-3′-phenyl-propionyl]imidazolidin-2-thioneC30H35N3O2S[α]D20 = +140.1 (c 0.47, CH2Cl2)Absolute configuration: (5S,2′R,3′S)Source of chirality: 1-phenylimidazolidin-2-thione induced Mannich reactions(5S,2′R,3′S)-5-(tert-Butyl)-3-phenyl-1-[2′-methyl-3′-(p-methoxyphenylamino)-3′-phenyl-propionyl]imidazolidin-2-thioneC30H35N3O2S[α]D20 = +148.7 (c 0.52, CH2Cl2)Absolute configuration: (5S,2′R,3′S)Source of chirality: 1-phenylimidazolidin-2-thione induced Mannich reactions(2R,3S)-Methyl 2-methyl-3-(p-methoxyphenylamino)-3-phenylpropanoateC18H21NO3[α]D20 = −51.1 (c 1.05, CH2Cl2)Absolute configuration: (2R,3S)Source of chirality: 1-phenylimidazolidin-2-thione induced Mannich reactions(2R,3S)-Methyl 2-methyl-3-(p-methoxyphenylamino)-3-(p-chloro-phenyl)propanoateC18H20ClNO3[α]D20 = −42.9 (c 0.55, CH2Cl2)Absolute configuration: (2R,3S)Source of chirality: 1-phenylimidazolidin-2-thione induced Mannich reactions(2R,3S)-Methyl 2-methyl-3-(p-methoxyphenylamino)-3-(m-nitro-phenyl)propanoateC18H20N2O5[α]D20 = −48.1 (c 1.10, CH2Cl2)Absolute configuration: (2R,3S)Source of chirality: 1-phenylimidazolidin-2-thione induced Mannich reactions(2R,3S)-Methyl 2-methyl-3-(p-methoxyphenylamino)-3-(2′,3′-dimethoxyphenyl)propanoateC20H25NO5[α]D20 = −53.2 (c 2.01, CH2Cl2)Absolute configuration: (2R,3S)Source of chirality: 1-phenylimidazolidin-2-thione induced Mannich reactions(2R,3S)-Methyl 2-methyl-3-(p-methoxyphenylamino)-3-(2′-furyl)-propanoate 5eC16H19NO4[α]D20 = −47.9 (c 1.10, CH2Cl2)Absolute configuration: (2R,3S)Source of chirality: 1-phenylimidazolidin-2-thione induced Mannich reactions(2R,3S)-Methyl 2-methyl-3-(p-methoxyphenylamino)-3-(2′-thienyl)-propanoateC16H19NO3S[α]D20 = −45.6 (c 1.06, CH2Cl2)Absolute configuration: (2R,3S)Source of chirality: 1-phenylimidazolidin-2-thione induced Mannich reactions

A new camphor-based 2-phenylimino-2-oxazolidine chiral auxiliary was prepared and it was shown to be a particularly effective chiral auxiliary for asymmetric alkylations affording high yields and diastereoselectivities. The alkylation products were readily cleaved by simple alkaline hydrolysis to give α-alkylated carboxylic acids in good yield and in almost enatiomerically pure form.A camphor-based 2-phenylimino-2-oxazolidine was used as a new chiral auxiliary for diastereoselective alkylations.

•The supported imidazolidinone was used to catalyze the 1,3-dipolar cycloadditions.•The products were obtained in good yields with excellent d.r. and ee.•Catalyst could be recycled for at least four times without loss of its activity.The tetraarylphosphonium supported chiral imidazolidinone catalyzes the enantioselective 1,3-dipolar cycloadditions of nitrones and α,β-unsaturated aldehydes to provide isoxazolidine aldehydes in good yields with excellent diastereo- and enantioselectivities. Most importantly, the tetraarylphosphonium supported imidazolidinone catalyst can be readily recovered and recycled for further transformations at least four cycles without observing significant decrease in yield and stereoselectivity.

Through the substitution reaction of hexachlorocyclotriphosphazene (HCCP) and 4,4′-diaminobiphenyl (DABP), a crosslinked polymer HCCP-DABP was synthesized by a conventional and convenient route. Owing to the strong coordination ability of pincer-type bis(amino) scaffold in the matrix, the polymer was successfully used as a support to form stable palladium catalyst complex Pd/HCCP-DABP. The palladium catalyst showed excellent reactivity in Suzuki-Miyaura cross-coupling reaction. In addition, the catalyst can be readily recovered and reused for further transformations at least 10 times without significant decrease in catalytic activity.

•Jørgensen–Hayashi's catalyst supported on POSS was prepared for the first time.•The POSS supported catalyst promoted the asymmetric Michael addition reactions efficiently.•The adduct products were obtained in good yields with good to excellent stereoselectivities.•Catalyst was recycled at least eight cycles without loss of its activity.The POSS supported (S)-α,α-diphenylprolinol trimethylsilyl ether catalyst was synthesized and applied in the asymmetric Michael addition reactions of aldehydes and arylnitroalkenes, providing the products in good yields with excellent enantioselectivities and good diastereoselectivities. The POSS supported catalyst can be readily recycled and reused for further transformations at least eight cycles without observing significant decrease in yield and stereoselectivity.The POSS supported (S)-α,α-diphenylprolinol trimethylsilyl ether catalyzes the asymmetric Michael addition reactions of aldehydes and arylnitroalkenes to provide the products in good yields with excellent enantioselectivities and good diastereoselectivities.Download high-res image (203KB)Download full-size image