172695-23-7

Upstream product

• 13435-20-6 tetraethylammoniumcyanide 
• 161529-21-1 (S)-(1-iodomethyl-2-methylpropyl)carbamic acid tert-butyl ester 
• 143-33-9 sodium cyanide 
• 126301-18-6 [(2S)-2-(tert-butoxycarbonylamino)-3-methyl-butyl] methanesulfonate 
• 2026-48-4 (S)-valinol 
• 13734-41-3 t-Boc-L-valine 
• 66866-46-4 C₁₅H₂₇NO₆ 
• 773837-37-9 sodium cyanide 
• 24424-99-5 di-tert-butyl dicarbonate 
• 79069-14-0 (S)-2-<(tert-butoxycarbonyl)amino>-3-methylbutan-1-ol 
• 72-18-4 L-valine 
• 122818-28-4 (S)-2-(N-tert-butoxycarbonylamino)-3-methylbutyl tosylate 

Downstream Products

• 5699-54-7 (R)-3-amino-4-methylpentanoic acid 
• 653589-25-4 (2S)-2-isopropyl-4,6-dioxopiperidine 
• 1174764-12-5 (2S,4R)-2-methyl-4-[({2-[(3R)-4-methyl-3-{methyl[(2S,3S)-3-methyl-2-({[(2R)-1-methylpiperidin-2-yl]carbonyl}amino)pentanoyl]amino}pentyl]-1,3-thiazol-4-yl}carbonyl)amino]-5-phenylpentanoic acid 
• 1219930-75-2 methyl (2S,4R)-2-methyl-4-[({2-[(3R)-4-methyl-3-{methyl[(2S,3S)-3-methyl-2-({[(2R)-1-methylpiperidin-2-yl]carbonyl}amino)pentanoyl]amino}pentyl]-1,3-thiazol-4-yl}carbonyl)amino]-5-phenylpentanoate 

Relevant academic research and scientific papers

Total Synthesis and Biological Evaluation of Natural and Designed Tubulysins

A streamlined total synthesis of N14-desacetoxytubulysin H (Tb1) based on a C-H activation strategy and a short total synthesis of pretubulysin D (PTb-D43) are described. Applications of the developed synthetic strategies and technologies to the synthesis of a series of tubulysin analogues (Tb2-Tb41 and PTb-D42) are also reported. Biological evaluation of the synthesized compounds against an array of cancer cells revealed a number of novel analogues (e.g., Tb14), some with exceptional potencies against certain cell lines [e.g., Tb32 with IC50 = 12 pM against MES SA (uterine sarcoma) cell line and 2 pM against HEK 293T (human embryonic kidney) cell line], and a set of valuable structure-activity relationships. The highly potent cytotoxic compounds discovered in this study are highly desirable as payloads for antibody-drug conjugates and other drug delivery systems for personalized targeted cancer chemotherapies.

DESACETOXYTUBULYSIN H AND ANALOGS THEREOF

In one aspect, the present disclosure provides tubulysin analogs of the formula (I) wherein R1, R2, R3, R4, X1, X2, X3, and A1 are as defined herein. In another aspect, the present disclosure also provides methods of preparing the compounds disclosed herein. In another aspect, the present disclosure also provides pharmaceutical compositions and methods of use of the compounds disclosed herein.

A multifaceted secondary structure mimic based on piperidine-piperidinones

Minimalist secondary structure mimics are typically made to resemble one interface in a protein-protein interaction (PPI), and thus perturb it. We recently proposed suitable chemotypes can be matched with interface regions directly, without regard for secondary structures. Here we describe a modular synthesis of a new chemotype 1, simulation of its solution-state conformational ensemble, and correlation of that with ideal secondary structures and real interface regions in PPIs. Scaffold 1 presents amino acid side-chains that are quite separated from each other, in orientations that closely resemble ideal sheet or helical structures, similar non-ideal structures at PPI interfaces, and regions of other PPI interfaces where the mimic conformation does not resemble any secondary structure. 68 different PPIs where conformations of 1 matched well were identified. A new method is also presented to determine the relevance of a minimalist mimic crystal structure to its solution conformations. Thus dld-1-faf crystallized in a conformation that is estimated to be 0.91 kcal-mol-1 above the minimum energy solution state. Do we know, when designing a new peptidomimetic scaffold like the one shown, how it can resemble secondary structures? Design and modular synthesis of this elongated mimic is reported, and the structure is related to ideal and real structures at PPI interfaces.

Entropy-controlled catalytic asymmetric 1,4-type Friedel-crafts reaction of phenols using conformationally flexible guanidine/bisthiourea organocatalyst

Soft and weak cooperation: Conformationally flexible organic compounds were found to promote the title transformation. These "soft" organocatalysts, which are able to control processes through the differential activation entropies (ΔΔS*S-R) of

Synthesis of novel N-protected β3-amino nitriles: study of their hydrolysis involving a nitrilase-catalyzed step

Several commercially available nitrilases were investigated with regard to their potential to hydrolyze N-protected β3-amino nitriles into their corresponding N-protected β3-amino acids. The biotransformations were obtained in different proportions depending on the nitrilase involved. The best hydrolysis results were achieved for the N-Cbz-β3-amino nitrile from l-alanine using the NIT-107, in a phosphate buffer at 0.05 M. However, no biotransformation into the corresponding acids was observed for the N-sulfonylamide β3-amino nitriles. Two simple and efficient procedures to prepare the β3-amino nitriles from their analogous α-amino acids are described. Thirty four new substances were synthesized and characterized over the course of this work.

Kinetic and NMR spectroscopic studies of chiral mixed sodium/lithium amides used for the deprotonation of cyclohexene oxide

The mixed-metal complex formed from n-butylsodium, n-butyllithium, and a chiral amino ether has been studied by NMR spectroscopy. Three different mixed-metal amides were used as chiral bases for the deprotonation of cyclohexene oxide. The selectivity and initial rate of reaction were compared for sodium-amido ethers, lithium-amido ethers, and mixtures of sodium and lithiumamido ethers in diethyl ether and tetrahydrofuran, respectively. The mixed sodium/lithium amides are more reactive than the single sodium and lithium amides, whereas the stereoselectivities are higher when lithium amides are used. The alkali-metal/γ-amido ethers exhibit both higher initial reaction rates and stereoselectivities than their β-amido ether analogues. NMR spectroscopic studies of mixtures of n-butylsodium (nBuNa), n-butyllithium (nBuLi), and the γ-amino ethers in diethyl ether show the exclusive formation of dimeric mixed-metal amides. In diethyl ether, the lithium atom of the mixed-metal amide is internally coordinated and the sodium atom is exposed to solvent; however, in tetrahydrofuran, both metals are internally coordinated.

Chemoenzymatic synthesis of 4-amino-2-hydroxy acids: A comparison of mutant and wild-type oxidoreductases

We describe a new chemoenzymatic synthesis of enantiopure 4-amino-2-hydroxy acids using two biotransformations in a single-pot process in aqueous medium. These compounds are valuable as γ-turn mimics for investigations into the secondary structure of peptides. The enzyme substrates are a series of carbobenzyloxy (CBZ)-protected 4-amino-2-keto esters, prepared efficiently from the L-amino acids, alanine, leucine, phenylalanine, and valine. First, the α-amino acids were converted to the corresponding β-amino acids in a simple five-step procedure. A further one-carbon homologation via ozonolysis of the corresponding β-keto cyanophosphoranes gave the required α-keto esters in good yield. The enzyme catalyzed hydrolyses of all the α-keto esters to the corresponding α-keto acids proceeded smoothly with the lipase from Candida rugosa. Using the same reaction pot, it was found that wild-type lactate dehydrogenases from either Bacillus stearothermophilus CBS-LDH) or Staphylococcus epidermidis (SE-LDH) could be used to specifically reduce the ketone of the alanine-derived α-keto acid 2, giving the (S)- and CR)-2-hydroxy acids, respectively, in good yields. However, the more bulky α-keto acids 3, 4, and 5 (derived from valine, leucine, and phenylalanine) were not substrates for these enzymes. In contrast, the genetically engineered H205Q mutant of D-hydroxyisocaproate dehydrogenase proved to be an ideal catalyst for the reduction of all the α-keto acids 2-5, giving excellent yields of the CBZ-protected (2R,4S)-4-amino2-hydroxy acids as single diastereomers. This genetically engineered oxidoreductase has great potential value in synthesis due to its broad substrate specificity and high catalytic activity. For example, reduction of 1 mmol of N-protected (S)-4-amino-2-oxopentanoic acid 2 took just 4 h with the H205Q mutant giving, after esterification, the CR)-2-alcohol 25 in 85% yield, whereas with SE-LDH the reaction required 4 days to give a 67% yield of 25.

Synthesis of homochiral N-Boc-β-aminoaldehydes from N-Boc-β-aminonitriles

Enantiopure N-Boc-β-aminoaldehydes are efficiently prepared in good yields from N-Boc-β-aminonitriles by reduction of the nitrile function with diisobutylaluminium hydride (DIBAL-H) - Keywords: β-aminoaldehyde; β-aminonitrile; α-aminoacid; homochiral; enantiomeric excess; reduction; DIBAL-H

Synthesis of enantiopure N-and C-protected homo-β-amino acids by direct homologation of α-amino acids

Enantiopure N-and/or C-protected homo-β-amino acids are prepared readily and in good yields from N-protected α-amino acids with the same side chain, via reduction of the carboxyl function and conversion of the resulting N-protected β-amino alcohol into the corresponding β-amino iodide and then β-amino cyanide. The key step of this strategy is represented by the synthesis of the enantiopure N-protected β-amino iodides 2 and 3 that are smoothly obtained from the parent amino alcohols 1 by polymer bound triarylphosphine-I2 complex in anhydrous dichloromethane.