253426-70-9

Usage

InChI:InChI=1/C18H27NO4S/c1-18(2,3)23-17(20)19-16(14-10-6-4-7-11-14)24(21,22)15-12-8-5-9-13-15/h5,8-9,12-14,16H,4,6-7,10-11H2,1-3H3,(H,19,20)

Upstream product

• 4248-19-5 tert-butyl carbazate 
• 873-55-2 sodium benzenesulfonate 
• 2043-61-0 cyclohexanecarbaldehyde 
• 515-42-4 sodium phenylsulfonate 
• 618-41-7 Benzenesulfinic acid 

Downstream Products

• 441071-06-3 ethyl 2-{2-cyclohexyl-2-[(tert-butoxycarbonyl)amino]ethyl}acrylate 
• 1323902-30-2 tert-butyl (cyclohexyl(ethylthio)methyl)carbamate 
• 1237535-01-1 tert-butyl [cyclohexyl(6-hydroxybenzo[d][1,3]dioxol-5-yl)methyl]carbamate 
• 1152292-82-4 tert-butyl (allyloxy)(cyclohexyl)methylcarbamate 

Relevant academic research and scientific papers

Asymmetric Aminalization via Cation-Binding Catalysis

Asymmetric cation-binding catalysis, in principle, can generate “chiral” anionic nucleophiles, where the counter cations are coordinated within chiral environments. Nitrogen nucleophiles are intrinsically basic, therefore, its use as nucleophiles is often challenging and limiting the scope of the reaction. Particularly, a formation of configurationally labile aminal centers with alkyl substituents has been a formidable challenge due to the enamine/imine equilibrium of electrophilic substrates. Herein, we report enantioselective nucleophilic addition reactions of potassium phthalimides to Boc-protected alkyl- and aryl-substituted α-amido sulfones. In situ generated imines smoothly reacted with the nitrogen nucleophiles to corresponding aminals with good to excellent enantioselectivitiy under mild reaction conditions. In addition, transformation of aminal products gave biologically relevant pyrrolidinone-fused hexahydropyrimidine scaffold with excellent stereoselectivity and good yield.

Copper-catalyzed borylative coupling of vinylazaarenes and N-Boc imines

Cu-catalyzed three-component couplings of vinylazaarenes, B2(pin)2, and N-Boc imines are described. Oxidation of the initially formed boronate gives azaarene-containing, Boc-protected amino alcohols with reasonable to good diastereoselectivities.

Enantioselective copper-catalyzed reductive coupling of vinylazaarenes with n -boc aldimines

The diastereo- and enantioselective reductive coupling of vinylazaarenes with N-Boc aldimines is described. The reactions proceed using chiral copper-bisphosphine complexes in the presence of TMDS as a hydride source to give reductive coupling products in moderate to high enantioselectivities.

Copper(I)-Catalyzed Asymmetric Pinacolboryl Addition of N-Boc-imines Using a Chiral Sulfoxide - Phosphine Ligand

Highly efficient and enantioselective copper(I)-catalyzed pinacolboryl addition of N-Boc-imines is reported. By using a single chiral sulfoxide-(dialkyl)phosphine (SOP) ligand, both enantiomeric isomers of α-amino boronic esters were obtained through an achiral counteranion switch.

Broad Spectrum Enolate Equivalent for Catalytic Chemo-, Diastereo-, and Enantioselective Addition to N-Boc Imines

Alkynyl ketones are attractive but challenging nucleophiles in enolate chemistry. Their susceptibility to other reactions such as Michael additions and the difficulty of controlling the enolate geometry make them difficult substrates. Mannich-type reactions, which previously have not been reported using N-carbamoyl-imines with simple ketone enolates, became our objective. In this report, we describe the first direct catalytic Mannich-type reaction between various ynones and N-Boc imines, whose stereocontrol presumably derives from catalyst control of enolate geometry. This method produces α-substituted β-amino ynones with excellent chemo-, diastereo-, and enantioselectivity. The products can be readily transformed into a broad range of molecular scaffolds upon further one-step transformations, demonstrating the utility of ynones as masked synthetic equivalents for a variety of unsymmetrically substituted acyclic ketones. In particular, alkynyl alkyl ketones resolve the long-standing problem of the inability to use the enolates of unsymmetrical dialkyl ketones lacking α-branching for regio- and stereoselective reactions.

Asymmetric disulfonimide-catalyzed synthesis of δ-amino-β-ketoester derivatives by vinylogous Mukaiyama-Mannich reactions

An organocatalytic asymmetric synthesis of δ-amino-β-ketoester derivatives has been developed. A chiral disulfonimide (DSI) serves as a highly efficient precatalyst for a vinylogous Mukaiyama-Mannich reaction of readily available dioxinone-derived silylox

Synthesis and structure-activity relationship studies of novel tubulysin U analogues-effect on cytotoxicity of structural variations in the tubuvaline fragment

Tubulysins are cytotoxic natural products with promising anti-cancer properties, originally isolated from myxobacterial cultures. Structurally, tubulysins are tetrapeptides, incorporating three unusual (Mep, Tuv and Tup) and one proteinogenic amino acid (Ile). Here we describe the synthesis and structure-activity relationship studies of novel tubulysin U and V analogues, with variations in the central Tuv fragment, which is known to be of paramount importance for tubulysins' potency and hence cytotoxicity, but has seldom been modified in previous studies. Specifically, we replaced the natural iso-propyl and acetoxy functionalities with other structurally related groups. In general, the new analogues showed much lower potency relative to native tubulysin U. However, one of the synthetic analogues (1f) having a MOM function replacing the acetyl group exhibited a 22 nM IC50 on the HT-29 cell line which is comparable to the IC50 displayed by tubulysin U (3.8 nM). Furthermore, the synthetic methodology reported herein was found to be flexible enough to deliver different core-modified tubulysin analogues and hence may be regarded as a scalable and convenient strategy for the chemical generation of novel tubulysin analogues.

A new family of cinchona-derived bifunctional asymmetric phase-transfer catalysts: Application to the enantio- and diastereoselective nitro-Mannich reaction of amidosulfones

A new family of bifunctional H-bond donor phase-transfer catalysts derived from cinchona alkaloids has been developed and evaluated in the enantio- and diastereoselective nitro-Mannich reaction of in situ generated N-Boc-protected imines of aliphatic, aromatic, and heteroaromatic aldehydes. Under optimal conditions, good reactivity and high diastereoselectivities (up to 24:1 dr) and enantioselectivities (up to 95% ee) were obtained using a 9-amino-9- deoxyepiquinidine-derived phase-transfer catalyst possessing a 3,5-bis(trifluoromethyl)phenylurea H-bond donor group at the 9-position.

Catalytic asymmetric synthesis of trisubstituted aziridines

A method is described which provides for the direct asymmetric catalytic synthesis of trisubstituted aziridines from imines and diazo compounds. While unactivated imines were not reactive to α-diazo carbonyl compounds in which the diazo carbon was disubstituted, N-Boc imines react with both α-diazo esters and α-diazo-N-acyloxazolidinones to give trisubstituted aziridines with excellent diastereo- and enantioselectivities.

A practical, one-pot multicomponent synthesis of α-amidosulfides and their application as latent N-acylimines in the Friedel-Crafts reaction

A novel one-pot, three-component synthesis of N-acyl or N-carbamoyl-α-amidosulfides 4 is described. The three-component reaction of aldehydes 1, primary carbamates (or amides) 2 and phenylsulfinic acid (6a) afforded α-amidosulfones 7, which after addition