Isocyanoacetate Derivatives: Synthesis, Reactivity, and Application

A Multicomponent Conjugation Strategy to Unique N‐Steroidal Peptides: First Evidence of the Steroidal Nucleus as a β‐Turn Inducer in Acyclic Peptides

“…To this end, a variety of peptide acids were produced through typical solution-phase protocols, [21] focusing on the installation of more (e.g., Ile) and less (e.g., Ala and Leu) sterically hindered C-terminal residues. Methyl isocyanoacetate and isocyanopeptides [22] were considered as isocyanide components to preserve the native characteristic of the peptide backbone. A variety of known steroidal amines [14a, 23] (i.e., androstanic, cholanic, cholestanic, spirostanic, and bis-norcholanic) was selected with the aim of assessing the influence of the stereochemistry (a or b) and position (steroidal nucleus or side chain) of the amino group on the chemical efficiency of the Ugi-4CR.…”

Characterization of Cu-ligand bonds in tris-pyrazolylmethane isocyanide copper(I) complexes based upon combined X-ray diffraction and theoretical study

“…The complexes [1][2][3](BF 4 ) were obtained by sequential addition of tpm ⁄ (1 equiv) and CNR (1 equiv) solutions in CH 2 Cl 2 to a solution of [Cu(NCMe) 4 ](BF 4 ) [49] in dichloromethane at 20-25°C, whereupon the reaction mixture was stirred for 30 min at 20-25°C, concentrated in vacuo until dryness and [1][2][3](BF 4 ) were isolated in excellent (95-98%) yields (see Scheme 1).…”

“…Metal-involving reactions of such versatile substrates as isocyanides attract significant attention, which is collaterally reflected in a large number of reviews and books published in this field [1][2][3][4][5][6][7][8]. Among various metal centers that promote conversion of RNC species, copper(I) plays a remarkable role insofar as this labile metal center provides efficient cyclization of isocyanides to various heterocyclic systems (for recent examples see [9][10][11][12][13][14]).…”

“…In this work, we consider another case of RNC ligation to a Cu I center, when coordination environment of the complex featuring three relatively good r-donor ligands and only one isocyanide as moderate r-donor and p-acceptor. For this study we addressed the complexes [Cu(tpm ⁄ )(CNR)](BF 4 ) (tpm ⁄ = tris (3,5-dimethylpyrazolyl)methane; R = Xyl [1](BF 4 ), 2-Cl-6-MeC 6 H 3 [2](BF 4 ), and Cy [3](BF 4 )) and conducted a combined X-ray structural and theoretical study to understand RNC ligand properties in these species. All our results are disclosed in sections that follow.…”

Complementary regioselectivity in the synthesis of iminohydantoins: remarkable effect of amide substitution on the cyclization

“…2 Besides the characteristic chemistry of isocyanides with a formally divalent carbon, 3 two different approaches have been employed for the cyclization, the use of the active methylene 4 and the use of the amide group, either through the oxygen 5 or nitrogen atom.…”