Diamidic and dicarbamic bispidinones show trans-cis isomerism, the relative population in solution of the cis form increasing with solvent polarity. The mutual proximity of the two amide functions in 4a has no impact on the barrier to isomerization. The system represents a peculiar case of planar chirality posing a challenge to its specification.

No abstract

The impact of a remote aromatic nucleus on the stereochemical outcome of the conjugate addition of α-sulfonylallylic carbanions to an α,β-unsaturated ester was investigated. α-Regioselectivity coupled with anti-diastereoselectivity is accompanied by a prominent preference for relative configuration 3 over 4. The 9-anthryl moiety has shown itself greatly superior over all other groups in this bias. A lithium ion-aromatic π interaction has been postulated as decisive for the remote transmission of chirality.

Four series of 1,3-diaza-2-functionalized-adamantan-6-one derivatives, bearing at the 2 position SO, SO₂, POCl and PO₂H functional groups, were synthesized via a key quadruple Mannich reaction, followed by transformation of an aminal functionality into the final 2-thia- and 2-phospha compounds. The compounds were tested for cytotoxic activity against the mouse B16-F10 melanoma cell line. Malignant melanoma is notorious for its high resistance to chemotherapy, and new anti-melanoma drugs are urgently needed. The 2-thia compounds exhibited poor proliferation inhibition activity, but the 2-phospha derivatives showed significant activity, with IC₅₀ values of 10-60 µM. The compounds induced cell death by G₂/M cell cycle arrest, which led to apoptosis, as determined by Annexin V-FITC/PI staining, mitochondrial membrane potential changes assessed by the JC-1 reagent, caspases 3 and 7 activation, and morphological changes.

No abstract