Intramolecular functional group differentiation as a strategy for the synthesis of bridged bicyclic β-amino acids

Abstract

Differentiation of identical electrophilic functional groups (carboxylates) by a strategically placed internal nucleophile (an amino group) in cyclic precursors was used as a key general approach to functionalized azabicyclic scaffolds.

Synthetic Access to Benzimidacarbocyanine Dyes to Tailor Their Aggregation Properties

“…The crude product (3.0742 g, 76% yield) was used without further purification. Spectral characterizations matched those found in the literature. , …”

“…This experiment was adapted from literature protocols. , Dimethyl-1,3-acetonedicarboxylate (4.0135 g, 23.046 mmol) was placed in a 50 mL RBF along with methanol (∼20 mL). The resulting clear and colorless solution was cooled in an ice bath prior to the portionwise addition of sodium borohydride (0.2517 g, 6.645 mmol).…”

Fluorine‐Labelled Spiro[3.3]heptane‐Derived Building Blocks: Is Single Fluorine the Best?

“…The latter compound can be prepared in four steps from well-documented diisopropyl 3-oxocyclobutane-1,1-dicarboxylate (2). [29][30][31] Following the convergent retrosynthetic strategy, several 2,2-difunctionallized 6-fluorospiro [3.3]heptanes can be prepared from 1, that in turn can be convenient common precursors for a large series of 6-fluorospiro [3.3] heptane-derived building blocks. (Scheme 1).…”

Conformationally Constrained Mono‐Fluorinated Arginine as a Cationic Label for Solid‐State 19F NMR Analysis of Membrane‐Bound Peptides

“…The molecular structure of 10 was confirmed by X‐ray crystallography . We anticipated that the formation of 10 would be helpful for the intramolecular differentiation of the two carboxylate groups in 9 . Six‐membered lactams are usually more resistant towards alkaline hydrolysis than esters; therefore, compound 10 was selectively modified only at the methyl carboxylate function.…”