Synthesis of Isoquinolones by Sequential Suzuki Coupling of 2-Halobenzonitriles with Vinyl Boronate Followed by Cyclization

Functionalized quinolones and isoquinolones via 1,2-difunctionalization of arynes: synthesis of antagonist agent AS2717638 and floxacin key intermediates

Quinolones and isoquinolones are privileged scaffolds in synthetic/medicinal chemistry and drug discovery due to their unique chemical structures and intrinsic properties. Herein, we reveal a transition-metal-free approach for their synthesis from the reaction of dimethyl-2-((phenylamino)methylene)malonate with aryne precursors under mild conditions. The substrate scope is broad, accommodating a wide range of functional groups. The synthetic utility of the developed protocol has been demonstrated in the total synthesis of the potent antagonist agent AS2717638 and key intermediates of floxacin congeners. The gram-scale experiments illustrate its synthetic potential.

Development of a Small Molecule Downmodulator for the Transcription Factor Brachyury

Brachyury is an oncogenic transcription factor whose overexpression drives chordoma growth. The downmodulation of brachyury in chordoma cells has demonstrated therapeutic potential, however, as a transcription factor it is classically deemed "undruggable". Given that direct pharmacological intervention against brachyury has proven difficult, attempts at intervention have instead targeted upstream kinases. Recently, afatinib, an FDA-approved kinase inhibitor, has been shown to modulate brachyury levels in multiple chordoma cell lines. Herein, we use afatinib as a lead to undertake a structure-based drug design approach, aided by mass-spectrometry and X-ray crystallography, to develop DHC-156, a small molecule that more selectively binds brachyury and downmodulates it as potently as afatinib. We eliminated kinase-inhibition from this novel scaffold while demonstrating that DHC-156 induces the post-translational downmodulation of brachyury that results in an irreversible impairment of chordoma tumor cell growth. In doing so, we demonstrate the feasibility of direct brachyury modulation, which may further be developed into more potent tool compounds and therapies.

Diversely functionalized isoquinolines and their core-embedded heterocyclic frameworks: a privileged scaffold for medicinal chemistry

Isoquinoline-enrooted organic small-molecules represent a challenging molecular target in the organic synthesis arsenal attributed to their structural diversity and therapeutic importance. Into the bargain, isoquinolines are significant structural frameworks in modern medicinal chemistry and drug development. Consequently, synthetic organic and medicinal chemists have been intensely interested in efficient synthetic tactics for the sustainable construction of isoquinoline frameworks and their derivatives in enantiopure or racemic forms. This review accentuates an overview of the literature on the modern synthetic approaches exploited in synthesising isoquinolines and their core embedded heterocyclic skeletons from 2021 to 2022. In detail, the methodologies and inspected pharmacological studies for the array of diversely functionalized isoquinolines or their core-embedded heterocyclic/carbocyclic structures involving the introduction of substituents at C-1, C-3, and C-4 carbon and N-2 atom, bond constructions at the C1-N2 atom and C3-N2 atom, and structural scaffolding within isoquinoline compounds have been reviewed. This intensive study highlights the need for and relevance of relatively unexplored bioisosterism employing isoquinoline-based small-molecules in drug design.

One-Pot Synthesis of 3-(1,2,3,4-Tetrahydroisoquinolin-1-yl)-isoquinolin-1(2H)-ones by DEAD-Promoted Oxidative Ugi–Wittig ­Reaction Starting from Phosphonium Salt Precursors

A new one-pot synthesis of 3-(1,2,3,4-tetrahydroisoquinolin-1-yl)-isoquinolin-1(2H)-ones by DEAD-promoted oxidative Ugi–­Wittig reaction was developed. The sequential reactions of (2-carboxybenzyl)triphenylphosphonium salts, isocyanides, and N-aryl-1,2,3,4-tetrahydroisoquinolines produced 3-(1,2,3,4-tetrahydroisoquinolin-1-yl)-isoquinolin-1(2H)-ones in moderate to good overall yields in the presence of DEAD and Et3N.