A simple asymmetric synthesis of 4-arylphenylalanines via palladium-catalyzed cross coupling reaction of arylboronic acids with tyrosine triflate

Shieh, Wen Chung; Carlson, John A.

doi:10.1021/jo00027a066

Cited by 105 publications

(31 citation statements)

References 2 publications

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“…I was previously prepared by reactions involving the extension of phenylene unit using p-methoxyphenyl boronic acid. 6 Cross-coupling 8,9 of I with II, using Pd(PPh 3 ) 4 as catalyst, yielded tetraethyl 3,3 ,4,4 -p-quinquephenyltetracarboxylate III in 63%. Subsequent hydrolysis of III afforded quinquephenyltetracarboxylic acid IV in 92%, and IV was converted to tetracarboxylic dianhydride V by heating in diphenyl ether (84%).…”

Section: Monomer Synthesismentioning

confidence: 99%

Synthesis and Characterization of Novel Aromatic Polyimides from Aromatic Diamine and 3,3””,4,4””-p-Quinquephenyltetracarboxylic Dianhydride

Morikawa

Hosoya

2002

Polym J

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ABSTRACT:A new rigid tetracarboxylic dianhydride, 3,3 ,4,4 -p-quinquephenyltetracarboxylic dianhydride, was synthesized in seven steps starting from diethyl 4-bromophthalate. New aromatic polyimides containing a pquinquephenyl unit were synthesized from this tetracarboxylic dianhydride and various aromatic diamines by the conventional two-step procedure of ring-opening polyaddition in a polar amide-type solvent and subsequent thermal cyclic dehydration. These polyimides had inherent viscosities of 0.20-1.20 dL g −1 , and were insoluble in organic solvents. The polyimides were characterized by differential scanning calorimetry (DSC), thermogravimetry (TG), wide-angle X-Ray diffraction measurements, and dynamic mechanical analysis (DMA). Typical polyimides had glass transition temperatures (T g ) at about 250 • C, and crystallized above T g s. The effects of p-quinquephenyl structure were reflected in the high storage modulus above the glass transition temperature. KEY WORDS 3,3 ,4,4 -p-Quinquephenyltetracarboxylic Dianhydride / Aromatic Polyimides / Glass Transition Temperature / Dynamic Storage Modulus / Aromatic polyimides are characterized by high glass transition temperature (T g ) along with high decomposition temperature and good mechanical properties, 1, 2 and are used in various fields including aerospace and electronics industries. The properties of the polyimides originate from unique aromatic heteroaromatic rings. Because of the rigidity of the ring, polyimides do not dissolve into organic solvents and melt without degradation. However, polyimides having rather rigid chemical structure between aromatic polyimide units exhibit high modulus and strength, 3, 4 and may be used to introduce highly rigid structure into polyimides and examine the properties of the polymers.Recently, we reported aromatic polyimides PI-Ar-m containing p-quarterphenyl (m = 2) 5 and p-sexiphenyl (m = 4) 6 unit, which were very rigid, and compared the properties of these polyimides with those of polyimides from 3,3 ,4,4 -p-terphenyltetracarboxylic dianhydride (m = 1) and 3,3 4,4 -biphenyltetracarboxylic dianhydride (m = 0), which have been previously prepared. 7 T g s were independent on the number of phenylene units (m) of the dianhydrides, while moduli were higher and decrement of moduli at the glass transition decreased with increasing m.We conducted the synthesis of a new rigid tetracarboxylic dianhydride, 3,3 ,4,4 -p-quinquephenyltetracarboxylic dianhydride, and aromatic polyimides (m = 3) were derived from it. This article is the first to report the synthesis and characterization of novel aromatic polyimides from tetracarboxylic dianhydride and aromatic diamines. The properties of polyimide, especially thermal behavior, are discussed. EXPERIMENTAL Materials4,4 -Diaminodiphenyl ether (VIa), 3,4 -diaminodiphenyl ether (VIb) 4,4 -diaminodiphenyl methane (VIc), m-phenylenediamine (VId), and p-phenylenediamine (VIe) were obtained commercially and purified by distillation under reduced pressure. 4,4 -bis(4-aminophenoxy)biphenyl (V...

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Section: Monomer Synthesismentioning

confidence: 99%

Synthesis and Characterization of Novel Aromatic Polyimides from Aromatic Diamine and 3,3””,4,4””-p-Quinquephenyltetracarboxylic Dianhydride

Morikawa

Hosoya

2002

Polym J

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“…This has compromised the utility of Suzuki coupling in many aspects and forced chemists to seek alternatives to standard conditions. Although some modifications in reaction parameters proved successful in a number of cases, [32] a general mild protocol is still highly desirable. Thus, the compatibility of selected common baselabile protective groups with our anhydrous protocol was investigated (Table 5).…”

Section: Resultsmentioning

confidence: 99%

Direct B‐Alkyl Suzuki–Miyaura Cross‐Coupling of Trialkyl‐ boranes with Aryl Bromides in the Presence of Unmasked Acidic or Basic Functions and Base‐Labile Protections under Mild Non‐Aqueous Conditions

Wang

Sun

Sun³

et al. 2009

Adv Synth Catal

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An efficient and chemoselective palladium-catalyzed direct B-alkyl Suzuki-Miyaura crosscoupling of trialkylboranes with diversely functionalized aryl bromides is described. A wide variety of unmasked acidic or basic functions are tolerated. The mild non-aqueous conditions are compatible with aldehydes, ketones, nitriles, chloro substitution as well as base-labile phenolic Piv and TBS protecting groups. The anhydrous conditions were found to be advantageous for aryl bromide substrates. A potent CEPT inhibitor was efficiently synthesised using this protocol.

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“…Initial work reported by Shieh et al described the derivatization of protected L-tyrosine triflate 10 with different aryl boronic acids [86]. By combination of Pd(PPh 3 ) 4 and anhydrous K 2 CO 3 in DMF ( Figure 3A), racemization was observed (an ee as low as 66% was observed).…”

Section: Access To and Derivatization Of (Pseudo)halogenated Aromaticmentioning

confidence: 95%

The Suzuki–Miyaura Cross-Coupling as a Versatile Tool for Peptide Diversification and Cyclization

et al. 2017

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Abstract:The (site-selective) derivatization of amino acids and peptides represents an attractive field with potential applications in the establishment of structure-activity relationships and labeling of bioactive compounds. In this respect, bioorthogonal cross-coupling reactions provide valuable means for ready access to peptide analogues with diversified structure and function. Due to the complex and chiral nature of peptides, mild reaction conditions are preferred; hence, a suitable cross-coupling reaction is required for the chemical modification of these challenging substrates. The Suzuki reaction, involving organoboron species, is appropriate given the stability and environmentally benign nature of these reactants and their amenability to be applied in (partial) aqueous reaction conditions, an expected requirement upon the derivatization of peptides. Concerning the halogenated reaction partner, residues bearing halogen moieties can either be introduced directly as halogenated amino acids during solid-phase peptide synthesis (SPPS) or genetically encoded into larger proteins. A reversed approach building in boron in the peptidic backbone is also possible. Furthermore, based on this complementarity, cyclic peptides can be prepared by halogenation, and borylation of two amino acid side chains present within the same peptidic substrate. Here, the Suzuki-Miyaura reaction is a tool to induce the desired cyclization. In this review, we discuss diverse amino acid and peptide-based applications explored by means of this extremely versatile cross-coupling reaction. With the advent of peptide-based drugs, versatile bioorthogonal conversions on these substrates have become highly valuable.

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A simple asymmetric synthesis of 4-arylphenylalanines via palladium-catalyzed cross coupling reaction of arylboronic acids with tyrosine triflate

Cited by 105 publications

References 2 publications

Synthesis and Characterization of Novel Aromatic Polyimides from Aromatic Diamine and 3,3””,4,4””-p-Quinquephenyltetracarboxylic Dianhydride

Synthesis and Characterization of Novel Aromatic Polyimides from Aromatic Diamine and 3,3””,4,4””-p-Quinquephenyltetracarboxylic Dianhydride

Direct B‐Alkyl Suzuki–Miyaura Cross‐Coupling of Trialkyl‐ boranes with Aryl Bromides in the Presence of Unmasked Acidic or Basic Functions and Base‐Labile Protections under Mild Non‐Aqueous Conditions

The Suzuki–Miyaura Cross-Coupling as a Versatile Tool for Peptide Diversification and Cyclization

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