Cyclic Trimers of Chiral Furan Amino Acids

Chakraborty, Tushar Kanti; Tapadar, Subhasish; Raju, Tuniki Venugopal; Annapurna, J.; Singh, Harjinder

doi:10.1055/s-2004-834807

Cited by 25 publications

(14 citation statements)

References 4 publications

(9 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…A plethora of domains such as catalysis, photonics, material science, can also be targeted. [33][34][35][36] We have been particularly interested in synthesizing tubes through controlled stacking of sufficiently rigid ring units 1-4; each unit consisted of a macrolactam [37][38][39][40][41][42][43][44] of C n symmetry (n = 2, 3, 4, Figure 1). [45,46] Owing to the vast potential of such compounds we looked for expedient and efficient syntheses.…”

Section: Introductionmentioning

confidence: 99%

Efficient Synthesis and Astonishing Supramolecular Architectures of Several Symmetric Macrolactams

Baillargeon

Bernard

Gauthier

et al. 2007

Chemistry A European J

View full text Add to dashboard Cite

The synthesis of four C(n) symmetric macrocyclic lactams cyclo-[NH-CH(2)-CH=CH-CH(2)-CO](n) (1, n=2; 2, n=3; 3, n=4) and cyclo-[NH-CH(2)-CH(2)-CH=CH-CO](3) (4) has been achieved by two approaches. A linear route leads to precursors that are subsequently macrocyclized in a separate step. The second, convergent approach relies on the symmetry of the targets: it includes suitably activated subunits, which are subjected to macrocyclization conditions. The subunits first oligomerize, then cyclize to form either pure macrolactams or mixtures. The macrolactam units 1, 2 and 4 stack on top each other through weak interactions (hydrogen bond and van der Waals), to form endless square, rectangular and triangular prisms, respectively. These stacks are further packed side by side in crystals grown from isotropic media. The overall dipoles in the crystals from lactams 1 and 4, which result mostly from the alignment of amide groups, are zero and large, respectively. Macrolactam 2 displays an astonishing isomorphism when allowed to cool down in anisotropic liquid crystal solutions. Large hollow hexagonal tubes are then obtained through a fractal process. Contrary to the three previous rings, 3 yields crystals where prisms of any shape are absent.

show abstract

Section: Introductionmentioning

confidence: 99%

Efficient Synthesis and Astonishing Supramolecular Architectures of Several Symmetric Macrolactams

Baillargeon

Bernard

Gauthier

et al. 2007

Chemistry A European J

View full text Add to dashboard Cite

show abstract

“…Our use of this approach complements substantial prior work by others who used an MCO strategy to prepare oligomeric esters and amides. Most notable is the use of activated seco -acids to form macrodiolides (and triolides) − and amidations of activated peptidic amino acids to construct the macrocyclic peptides valinomycin and westiellamide. − A common feature to these amidation reactions is a five-membered heterocycle, such as a thiazole or oxazole, installed in the peptide backbone. − This presumably enhances a conformation more favorable for cyclization.…”

Section: Results and Discussionmentioning

confidence: 99%

The Formation of Impossible Rings in Macrocyclooligomerizations for Cyclodepsipeptide Synthesis: The 18-from-12 Paradox

Smith

Johnston

2021

J. Org. Chem.

View full text Add to dashboard Cite

A reinvestigation into the macrocyclooligomerization (MCO) of a tetradepsipeptide is reported, uncovering a paradox in which the MCO of depsipeptide monomers can produce “impossible” ring sizes: a 12-atom chain produced the expected 24-membered ring, alongside unexpected 18- and 30-membered cyclic oligomeric depsipeptides (CODs). We report an alternative preparation of authentic 18- and 36-membered macrocycles for this case using a stepwise synthesis that provides definitive analytical characterization for each ring size. Our investigation yields a recharacterization and reassignment of two macrocycles originally reported in this MCO series, along with updated yields and isothermal titration calorimetry data after implementation of new critical protocols for purification and subsequent analysis. Initial studies to probe this mechanistic conundrum are described.

show abstract

“…In further studies, optically active derivatives of H-Faa-OH were synthesized as well as their symmetric optically active macrocyclic trimers 236a−c. 111 The starting materials in this synthesis are chiral N-Boc-amino aldehydes 230a−c derived from the corresponding amino acids and (S)- Calculations showed that in comparison with 226, compounds 236a−c are not planar. 111 The incorporation in the structure of chiral side chains changes the planar geometry of these trimers to the form of a tripod bowl with S-cisorientation of all amide carbonyls and NH bonds directed to the same side.…”

Section: Furans In Macrocyclic Peptide Scaffoldsmentioning

confidence: 99%

“…111 The starting materials in this synthesis are chiral N-Boc-amino aldehydes 230a−c derived from the corresponding amino acids and (S)- Calculations showed that in comparison with 226, compounds 236a−c are not planar. 111 The incorporation in the structure of chiral side chains changes the planar geometry of these trimers to the form of a tripod bowl with S-cisorientation of all amide carbonyls and NH bonds directed to the same side. The torsion angle of HN-Cα-H for both 236a and 236c is ∼175°, and it is ∼180°(trans) for 236b.…”

Section: Furans In Macrocyclic Peptide Scaffoldsmentioning

confidence: 99%

Heteroaryl Rings in Peptide Macrocycles

2019

View full text Add to dashboard Cite

This Review is devoted to the chemistry of macrocyclic peptides having heterocyclic fragments in their structure. These motifs are present in many natural products and synthetic macrocycles designed against a particular biochemical target. Thiazole and oxazole are particularly common constituents of naturally occurring macrocyclic peptide molecules. This frequency of occurrence is because the thiazole and oxazole rings originate from cysteine, serine, and threonine residues. Whereas other heteroaryl groups are found less frequently, they offer many insightful lessons that range from conformational control to receptor/ligand interactions. Many options to develop new and improved technologies to prepare natural products have appeared in recent years, and the synthetic community has been pursuing synthetic macrocycles that have no precedent in nature. This Review attempts to summarize progress in this area.

show abstract

Cyclic Trimers of Chiral Furan Amino Acids

Cited by 25 publications

References 4 publications

Efficient Synthesis and Astonishing Supramolecular Architectures of Several Symmetric Macrolactams

Efficient Synthesis and Astonishing Supramolecular Architectures of Several Symmetric Macrolactams

The Formation of Impossible Rings in Macrocyclooligomerizations for Cyclodepsipeptide Synthesis: The 18-from-12 Paradox

Heteroaryl Rings in Peptide Macrocycles

Contact Info

Product

Resources

About