172695-33-9Relevant articles and documents
TUBULYSIN DERIVATIVES AND METHODS FOR PREPARING THE SAME
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Page/Page column 22, (2020/02/16)
The invention relates to novel means and methods for the synthesis of tubulysin and derivatives thereof, which find their use e.g. as cytotoxic agents in targeted drug delivery. Provided is a method for preparing a tubulysin derivative, comprising reacting compounds A, B and C in a 3- component Passerini reaction, wherein compound A is a carboxylic acid according to the general formula (A); wherein compound B is an aldehyde according to the general formula (B); and wherein compound C is an isocyanide according to the general formula (C).
Tubulysin Synthesis Featuring Stereoselective Catalysis and Highly Convergent Multicomponent Assembly
Vishwanatha, Thimmalapura M.,Giepmans, Ben,Goda, Sayed K.,D?mling, Alexander
supporting information, p. 5396 - 5400 (2020/07/08)
A concise and modular total synthesis of the highly potent N14-desacetoxytubulysin H (1) has been accomplished in 18 steps in an overall yield of up to 30percent. Our work highlights the complexity-augmenting and route-shortening power of diastereoselective multicomponent reaction (MCR) as well as the role of bulky ligands to perfectly control both the regioselective and diastereoselective synthesis of tubuphenylalanine in just two steps. The total synthesis not only provides an operationally simple and step economy but will also stimulate major advances in the development of new tubulysin analogues.
A novel synthesis of N-but-3-enyl-α- and β-amino acids
Van Nguyen,Brownlee, Robert T. C.,Hughes, Andrew B.
experimental part, p. 1991 - 1998 (2010/03/24)
N-But-3-enyl-α- and β-amino acids can be prepared by cleaving 1,3-oxazolidin-5-ones and 1,3-oxazinan-6-ones in the presence of allylsilanes and boron trifluoride etherate at room temperature in good to excellent yields. Georg Thieme Verlag Stuttgart.
Homologation of α-amino acids to β-amino acids: 9-Fluorenylmethyl chloroformate as a carboxyl group activating agent for the synthesis of Nα-protected aminoacyldiazomethanes
Kantharaju,Suresh Babu, Vommina V.
, p. 2152 - 2158 (2007/10/03)
An efficient and stereospecific homologation of urethane-protected α-amino acids to β-amino acids by Arndt-Eistert approach using an equimolar mixture of Fmoc-/Boc-/Z-α-amino acid and 9-fluorenylmethyl chloroformate for the acylation of diazomethane synth
Synthesis of β-amino acids: 2-(1H-benzotriazol-1-yl)-1,1,3,3-tetramethyl-uronium tetrafluoroborate (TBTU) for activation of Fmoc-/Boc-/Z-α-amino acids
Patil, Basanagoud S.,Vasanthakumar, Ganga-Ramu,Suresh Babu
, p. 3089 - 3096 (2007/10/03)
A new and efficient method for the homologation of urethane protected α-amino acids to its β-homomers by the Arndt-Eistert method using TBTU as a coupling agent is described. Several Fmoc-/Boc-/Z-protected α-amino diazoketone derivatives have been obtaine
Synthesis of Fmoc-/Boc-/Z-β-amino acids via Arndt-Eistert homologation of Fmoc-/Boc-/Z-α-amino acids employing BOP and PyBOP
Vasanthakumar,Babu, V. V. Suresh
, p. 1691 - 1695 (2007/10/03)
A simple and efficient protocol for Arndt-Eistert chain homologation of Fmoc-/Boc-/Z-α-amino acids using BOP or PyBOP as a coupling agent to the corresponding β-amino acids, synthesizing the key intermediate α-diazoketones as crystalline solids in good yield is described.
A convenient method for the synthesis of β-amino acids via the Arndt-Eistert approach using p-toluenesulphonyl chloride as a carboxylic group activating agent
Vasanthakumar, Ganga-Ramu,Suresh Babu, Vommina V.
, p. 651 - 657 (2007/10/03)
A simple method for the synthesis of Z-/Boc-/Fmoc-protected β-amino acids by the Arndt-Eistert approach employing p-toluenesulphonyl chloride for the activation of the carboxyl group of Nα-protected amino acid is described. The method is rapid and gave good yields with opitical purity.
Homologation of α-amino acids to β-amino acids using Boc2O
Vasanthakumar, Ganga-Ramu,Patil, Basanagoud S.,Suresh Babu, Vommina V.
, p. 2087 - 2089 (2007/10/03)
The use of Boc2O as a coupling agent in the homologation of N-urethane protected-α-amino acid to its β-homomers by the Arndt-Eistert method is described. The homologation gives good yields without racemization. The use of Boc2O as a
Convenient and simple synthesis of N-{[(9H-fluoren-9- yl)methoxy]carbonyl}-(Fmoc) protected β-amino acids (=homo-α-amino acids) employing Fmoc-α-amino acids and dicyclohexylcarbodiimide(DCC) mixtures
Ananda,Suresh Babu
, p. 418 - 423 (2007/10/03)
A simple approach for the homologation of α-amino acids to β-amino acids by the Arndt-Eistert method employing Fmoc-α-amino acid and N, N1- dicyclohexylcarbodiimide (DCC) mixture for the acylation of diazomethane, synthesizing the key intermediates Fmoc-α-amino acyldiazomethanes as crystalline solids is described.
Preparation of N-Fmoc-Protected β2- and β3-Amino Acids and Their Use as Building Blocks for the Solid-Phase Synthesis of β-Peptides
Guichard, Gilles,Abele, Stefan,Seebach, Dieter
, p. 187 - 206 (2007/10/03)
N-Fmoc-Protected (Fmoc = (9H-fluoren-9-ylmethoxy)carbonyl) β-amino acids are required for an efficient synthesis of β-oligopeptides on solid support. Enantiomerically pure Fmoc-β3-amino acids (β3: side chain and NH2 at C(3)(=C(β))) were prepared from Fmoc-protected (S)- and (R)-α-amino acids with aliphatic, aromatic, and functionalized side chains, using the standard or an optimized Arndt-Eistert reaction sequence. Fmoc-β2-Amino acids (β2 side chain at C(2), NH2 at C(3)(=C(β))) configuration bearing the side chain of Ala, Val, Leu, and Phe were synthesized via the Evans' chiral auxiliary methodology. The target β3-heptapeptides 5-8, a β3- pentadecapeptide 9 and a β2-heptapeptide 10 were synthesized on a manual solid-phase synthesis apparatus using conventional solid-phase peptide synthesis procedures (Scheme 3). In the case of β3-peptides, two methods were used to anchor the first β-amino acid: esterification of the ortho-chlorotrityl chloride resin with the first Fmoc-β-amino acid 2 (Method I, Scheme 2) or acylation of the 4-(benzyloxy)benzyl alcohol resin (Wang resin) with the ketene intermediates from the Wolff rearrangement of amino-acid-derived diazo ketone 1 (Method II, Scheme 2). The former technique provided better results, as exemplified by the synthesis of the heptapeptides 5 and 6 (Table 2). The intermediate from the Wolff rearrangement of diazo ketones 1 was also used for sequential peptide-bond formation on solid support (synthesis of the tetrapeptides 11 and 12). The CD spectra of the β2- and β3-peptides 5, 9. and 10 show the typical pattern previously assigned to an (M) 31 helical secondary structure (Fig.). The most intense CD absorption was observed with the pentadecapeptide 9 (strong broad negative Cotton effect at ca. 213 nm); compared to the analogous heptapeptide 5, this corresponds to a 2.5 fold increase in the molar ellipticity per residue!
