Peptide side-arm derivatives of lariat ethers and bibracchial lariat ethers: syntheses, cation binding properties, and solid state structural data

Convenient Synthesis of Ferrocene Conjugates Mediated by Benzyltriethylammonium Tetrathiomolybdate in a Multi‐Step Tandem Process

“…Our next goal was to synthesize amino acid and peptide conjugates of ferrocene using our protocol via N and C termini and via side chains of amino acids. Initially, for conjugation of amino acids and peptides via their N ‐terminus we synthesized chloroacetamides of L ‐phenylalanine ( 15 ), valine ( 16 ) and the dipeptide 20 14. When these were treated with 4 and 5 (Scheme ) we could conveniently isolate monovalent ( 15a , 16a and 20a ) and divalent conjugates ( 15b , 16b and 20b ) in very good yields (Table 3).…”

Towards the Synthesis of Highly Hindered Pyrrolidines by Intramolecular AAC Click Reactions: What Can Be Learned from DFT Calculations?**

“…Further conversion of the primary alcohol to the corresponding chloride gave 12 in good overall yield [22] . On the other hand, ester 10 was prepared by bubbling HCl into a solution of alanine ( 13 ) and propargyl alcohol [23] . With the two key fragments in hand, we foresaw their condensation to obtain the imino ester 8 .…”

New Macrocycles with Planar Chirality—Synthesis and Determination of Absolute Configurations

“…X-ray studies: The synthesized diazacoronands crystallized readily under diffusive conditions and single crystals suitable for X-ray analysis were obtained for compounds [1][2][3]19 and 20, and 23.…”

“…The solvent was then evaporated and the residue was purified by column chromatography (silica gel; AcOEt/MeOH 95:5 or 8:2 for 23 and 24, respectively) to give the desired product. 2, 153.1, 147.7, 145.8, 130.6, 128.6, 128.5, 128.4, 128.2, 127.5, 125.6, 121.0, 113.5, 112.2, 111.4, 111.3, 76.5 2,153.1,147.4,145.7,144.2,139.3,136.3,128.5,128.2,127.9,125.6,117.3,111.6,111.4,111.3,110.0,76.4 (CH 2 Ph),71.1,71.0,67.3,67.2,38.8,38.7,34.3,31.4 2 H;CONH),2 H),3 H),7.09 (t,3 2,153.1,148.6,147.2,139.4,136.2,129.0,128.6,128.5,128.1,125.7,123.5,115.5,113.1,112.8,111.5,111.3,76.8 (CH 2 Ph),71.0,70.1,67.6,67.4,38.7,38.6 168.8 (CONH),…”

“…[1] Over the last few decades, large numbers of chiral macrocyclic receptors have been synthesized and subjected to host-guest investigations. Most of these have a center [2] and/or an axis [3] as a chiral element, but less attention has been paid to receptors possessing planar chirality. This is probably because planar chiral macrocyclic compounds are based mostly on small, rigid cyclophane backbones with smaller numbers of donor atoms [4] and, although suitable for construction of ligands for asymmetric synthesis, [5] they are completely inefficient in supramolecular applications.…”