Concise Synthesis of Functionalized Benzocyclobutenones.

A concise approach to access functionalized benzocyclobutenones from 3-halophenol derivatives is described. This modified synthesis employs a [2+2] cycloaddition between benzynes generated from dehydrohalogenation of aryl halides using LiTMP and acetaldehyde enolate generated from n-BuLi and THF, followed by oxidation of the benzocyclobutenol intermediates to provide benzocyclobutenones. The [2+2] reaction can be run on a 10-gram scale with an increased yield. A number of functional groups including alkenes and alkynes are tolerated. Coupling of benzynes with ketene silyl acetals to give 8-substituted benzocyclobutenones is also demonstrated.

Rhodium(I)-catalyzed decarbonylative spirocyclization through C-C bond cleavage of benzocyclobutenones: an efficient approach to functionalized spirocycles.

The rhodium-catalyzed formation of all-carbon spirocenters involves a decarbonylative coupling of trisubstituted cyclic olefins and benzocyclobutenones through CC activation. The metal-ligand combination [{Rh(CO)2 Cl}2 ]/P(C6 F5 )3 catalyzed this transformation most efficiently. A range of diverse spirocycles were synthesized in good to excellent yields and many sensitive functional groups were tolerated. A mechanistic study supports a hydrogen-transfer process that occurs through a ß-H elimination/decarbonylation pathway.

A molecular glue degrader of the WIZ transcription factor for fetal hemoglobin induction.

Sickle cell disease (SCD) is a prevalent, life-threatening condition attributable to a heritable mutation in ß-hemoglobin. Therapeutic induction of fetal hemoglobin (HbF) can ameliorate disease complications and has been intently pursued. However, safe and effective small-molecule inducers of HbF remain elusive. We report the discovery of dWIZ-1 and dWIZ-2, molecular glue degraders of the WIZ transcription factor that robustly induce HbF in erythroblasts. Phenotypic screening of a cereblon (CRBN)-biased chemical library revealed WIZ as a previously unknown repressor of HbF. WIZ degradation is mediated by recruitment of WIZ(ZF7) to CRBN by dWIZ-1, as resolved by crystallography of the ternary complex. Pharmacological degradation of WIZ was well tolerated and induced HbF in humanized mice and cynomolgus monkeys. These findings establish WIZ degradation as a globally accessible therapeutic strategy for SCD.

Highly enantioselective Rh-catalyzed carboacylation of olefins: efficient syntheses of chiral poly-fused rings.

Here we report the first highly enantioselective Rh-catalyzed carboacylation of olefins via C-C bond activation of benzocyclobutenones. Good yields and excellent enantioselectivities (92-99% ee, 14 examples) were obtained for substrates with various steric and electronic properties. In addition, fully saturated poly-fused rings were prepared from the carboacylation products through a challenging catalytic reductive dearomatization approach. These investigations provide a distinct way to prepare chiral carbon frameworks that are nontrivial to access with conventional methods.

Chemoproteomics Enabled Discovery of Selective Probes for NuA4 Factor BRD8.

Bromodomain-containing proteins frequently reside in multisubunit chromatin complexes with tissue or cell state-specific compositions. Recent studies have revealed tumor-specific dependencies on the BAF complex bromodomain subunit BRD9 that are a result of recurrent mutations afflicting the structure and composition of associated complex members. To enable the study of ligand engaged complex assemblies, we established a chemoproteomics approach using a functionalized derivative of the BRD9 ligand BI-9564 as an affinity matrix. Unexpectedly, in addition to known interactions with BRD9 and associated BAF complex proteins, we identify a previously unreported interaction with members of the NuA4 complex through the bromodomain-containing subunit BRD8. We apply this finding, alongside a homology-model-guided design, to develop chemical biology approaches for the study of BRD8 inhibition and to arrive at first-in-class selective and cellularly active probes for BRD8. These tools will empower further pharmacological studies of BRD9 and BRD8 within respective BAF and NuA4 complexes.