Disulfide re-bridging reagents for single-payload antibody-drug conjugates.

Numerous antibody-drug conjugate (ADC) linker technologies exist for the synthesis of ADCs with drug-to-antibody ratios (DARs) being an even integer (typically 2, 4 or 8). However, ADCs with odd-integer DARs are significantly harder to synthesise. Here, we report the synthesis of ADCs loaded with a single warhead, using TetraDVP linkers which simultaneously re-bridge all four interchain disulfides of an IgG1 antibody.

Synthesis of sp3-rich heterocyclic frameworks by a divergent synthesis strategy.

Fragment-based lead discovery (FBLD) often relies on flat, aromatic compounds which display undesirable physicochemical properties with limited exit vectors for fragment growth. Herein, we report concise synthetic strategies to sp3-rich heterocyclic fragments encompassing polar exit vectors poised for fragment-to-lead (F2L) development.

Photocatalytic methods for amino acid modification.

Amino acid modification plays an important role across several fields, including synthetic organic chemistry, materials science, targeted drug delivery and the probing of biological function. Although a myriad of methods now exist for the modification of peptides or proteins, many of these target a handful of the most reactive proteinogenic amino acids. Photocatalysis has recently emerged as a mild approach for amino acid modification, generating a sizable toolbox of reactions capable of modifying almost all of the canonical amino acids. These reactions are characterised by their mild, physiologically compatible conditions, greatly enhancing their usefulness for amino acid modification. This review aims to introduce the field of photocatalytic amino acid modification and discusses the most recent advances.

C(sp3)-H arylation to construct all-syn cyclobutane-based heterobicyclic systems: a novel fragment collection.

All-syn fused cyclobutanes remain an elusive chemotype and thus present an interesting synthetic challenge. Herein, we report the successful application of Pd-catalysed C(sp3)-H arylation of cyclobutane compounds to generate all-syn heterobicyclic fragments using an innovative 'inside-out' approach. Through this strategy we generate a virtual collection of 90 fragments, which we demonstrate to have enhanced three-dimensionality and superior fragment-like properties compared to existing collections.

An efficient, stereocontrolled and versatile synthetic route to bicyclic partially saturated privileged scaffolds.

Herein, we describe the development of a simple, high yielding and stereocontrolled strategy for the synthesis of a series of triazolopiperazines and other biologically relevant fused scaffolds from optically active amino acids. This route was applied to the synthesis of 22 scaffolds containing new, previously inaccessible vectors and used to access a novel analogue of ganaplacide.

Cycloaddition Strategies for the Synthesis of Diverse Heterocyclic Spirocycles for Fragment-Based Drug Discovery.

In recent years the pharmaceutical industry has benefited from the advances made in fragment-based drug discovery (FBDD) with more than 30 fragment-derived drugs currently marketed or progressing through clinical trials. The success of fragment-based drug discovery is entirely dependent upon the composition of the fragment screening libraries used. Heterocycles are prevalent within marketed drugs due to the role they play in providing binding interactions; consequently, heterocyclic fragments are important components of FBDD libraries. Current screening libraries are dominated by flat, sp2-rich compounds, primarily owing to their synthetic tractability, despite the superior physicochemical properties displayed by more three-dimensional scaffolds. Herein, we report step-efficient routes to a number of biologically relevant, fragment-like heterocyclic spirocycles. The use of both electron-deficient and electron-rich 2-atom donors was explored in complexity-generating [3+2]-cycloadditions to furnish products in 3 steps from commercially available starting materials. The resulting compounds were primed for further fragment elaboration through the inclusion of synthetic handles from the outset of the syntheses.

Strategies for the Diversity-Oriented Synthesis of Macrocycles.

Macrocycles have long been recognized as useful chemical entities for medicine, with naturally occurring and synthetic macrocycles clinically approved for use as prescription drugs. Despite this promise, the synthesis of collections of macrocycles has been historically challenging due to difficulties in the formation of large rings. Diversity-Oriented Synthesis (DOS) emerged in the early 2000s as a powerful strategic solution to the construction of diverse molecular libraries. This review details the various strategies developed within the field of DOS for the synthesis of macrocycle libraries, utilizing modern synthetic methodology to deliver structurally diverse collections of macrocyclic molecules, and the exploration of their therapeutic potential. Section 1 of this work details the use of algorithmic strategies and is divided into Build/Couple/Pair, Advanced Build/Couple/Pair, Initiate/Propagate/Terminate, Fragment-Based Domain Shuffling, Two-Directional Synthesis, and Successive Ring Expansion. Section 2 covers strategies based on ring distortion reactions, including Sequential Cycloaddition/Fragmentation, Ring Expansions, and Miscellaneous.