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Introduction: The chromatin factor BRD9 is a genetic dependency in some cancers, often referred to as SMARCB1-perturbed cancers. Two types of genetic alterations result in SMARCB1 perturbation: SS18-SSX gene fusion and SMARCB1 loss-of-function mutations. In synovial sarcoma, a rare and aggressive soft tissue malignancy comprising approximately 10% of all soft tissue sarcomas, the presence of the SS18-SSX fusion gene drives the disruption of SMARCB1 function and leads to a synthetic lethal dependence on BRD9. In SMARCB1-null solid tumors, for example malignant rhabdoid tumors (MRT), poorly differentiated chordomas, and epithelioid sarcomas, the absence of SMARCB1 protein results in a similar BRD9 dependence. Thus, in SMARCB1-perturbed cancers, including synovial sarcoma and SMARCB1-null cancers, degradation of BRD9 is hypothesized to result in an anticancer effect. CFT8634 is an orally bioavailable heterobifunctional degrader that induces ternary complex formation with BRD9 and an E3 ligase, leading to the ubiquitination of BRD9 and its subsequent degradation by the proteasome. Results: Here we describe the chemical structure of CFT8634 and an overview of the medicinal chemistry path leading to its discovery. In vitro, CFT8634 promotes rapid, potent, deep, and selective degradation of BRD9 with a half-maximal degradation concentration (DC50) of 2 nM in a synovial sarcoma cell line. In long-term growth assays, CFT8634 is effective at impairing cell growth in a concentration-dependent manner specifically in SMARCB1-perturbed contexts. In vivo, oral dosing of CFT8634 in xenograft models of SMARCB1-perturbed cancers leads to robust and dose-dependent degradation of BRD9, which translates to significant and dose-dependent inhibition of tumor growth in preclinical xenograft models. Conclusion: The preclinical data presented herein support the clinical development of CFT8634 for the treatment of synovial sarcoma and SMARCB1-null tumors. Citation Format: Katrina L. Jackson, Roman V. Agafonov, Mark W. Carlson, Prasoon Chaturvedi, David Cocozziello, Kyle Cole, Richard Deibler, Scott J. Eron, Andrew Good, Ashley A. Hart, Minsheng He, Christina S. Henderson, Hongwei Huang, Marta Isasa, R. Jason Kirby, Linda Lee, Michelle Mahler, Moses Moustakim, Christopher G. Nasveschuk, Michael Palmer, Laura L. Poling, Roy M. Pollock, Matthew Schnaderbeck, Stan Spence, Gesine K. Veits, Jeremy L. Yap, Ning Yin, Rhamy Zeid, Adam S. Crystal, Andrew J. Phillips, Stewart L. Fisher. The discovery and characterization of CFT8634: A potent and selective degrader of BRD9 for the treatment of SMARCB1-perturbed cancers [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr ND09.

In addition to the therapeutic applicability of targeted protein degradation (TPD), the modality also harbors unique properties that enable the development of innovative chemical biology tools to interrogate complex biology. TPD offers an all-chemical strategy capable of the potent, durable, selective, reversible, and time-resolved control of the levels of a given target protein in both in vitro and in vivo contexts. These properties are particularly well-suited for enabling the precise perturbation of a given gene to understand its biology, identify dependencies/vulnerabilities in disease contexts, and as a strategy to control gene therapies. To leverage these elegant properties, we developed the AchillesTag (aTAG) degradation system to serve as a tool in target identification and validation efforts. The aTAG degradation system provides a novel degradation tag based on the MTH1 protein paired with three fully validated bifunctional degraders with both in vitro and in vivo applicability. We catalog the development of the aTAG system from selection and validation of the novel MTH1 aTAG, alongside a comprehensive SAR campaign to identify high performing tool degraders. To demonstrate the utility of the aTAG system to dissect a complex biological system, we apply the technology to the control of Chimeric Antigen Receptor (CAR) activity. Using aTAG, we demonstrate the ability to potently and selectively control CAR protein levels, resulting in the exquisite rheostat control of CAR mediated T-cell activity. Furthermore, we showcase the in vivo application of the system via degradation of the aTAG-fused CAR protein in a human xenograft model. The aTAG degradation system provides a complete chemical biology tool to aid foundational target validation efforts that inspire drug discovery campaigns towards therapeutic applicability.

The rolling contact fatigue resistance of austempered ductile iron (ADI) produced at various holding times was evaluated by using a twin-disk rolling configuration rig. The resulting fatigue life of ADI samples was compared with that of conventional quenched and tempered (Q&T) ductile iron samples with the same chemical composition. It was found that the macro hardness of ADI samples decreased and the fatigue life became shorter for longer holding time. For similar macro hardness, ADI samples had higher fatigue resistance as compared with Q&T ductile iron samples. Optical microscopy and scanning electron microscopy indicated that the graphite nodules acted as crack nucleation sites for the ductile iron. The cracks propagated towards either the surface or adjacent graphite nodules until the formation of pits or spalls occurred. The excellent fatigue resistance of ADI samples could be attributed to the increase of surface hardness which was caused by the strain induced transformation of retained austenite into martensite. By using X-ray diffraction, the difference of retained austenite present in the wear track and off the wear track ranged from 4.42% to 26.15%.

Process research, development, and manufacture of TP-808 (1), a key intermediate for the discovery and manufacture of tetracycline analogues, is described. The process used for the preparation of 1 avoids chromatographic purifications and has been substantially improved over the previously reported preparation. The robustness of the process was demonstrated in a 76.1 kg manufacturing campaign with 56% overall yield.

Process research and development of the fully synthetic broad spectrum tetracycline TP-2758, with a chiral pyrrolidine side chain at the C-8 position, is described. The process utilizes two key intermediates, 7 and 10, in a convergent approach that allows for manufacturing of sufficient quantities of API to supply preclinical and early clinical development. The pyrrolidine moiety was introduced into the left-hand piece (LHP) 10 with high enantioselectivity using Ellman’s sulfinamide chemistry, and the absolute configuration was confirmed by X-ray crystal structure analysis.

The C-8 position of the tetracyclines has been largely underexplored because of limitations in traditional semisynthetic techniques. Employing a total synthetic approach allowed for modifications at the C-7 and C-8 positions, enabling the generation of structure-activity relationships for overcoming the two most common tetracycline bacterial-resistance mechanisms: ribosomal protection (tet(M)) and efflux (tet(A)). Ultimately, several compounds were identified with balanced activity against both Gram-positive and Gram-negative bacteria, including pathogens bearing both types of tetracycline-resistance mechanisms. Compounds were screened in a murine systemic infection model to rapidly identify compounds with oral bioavailability, leading to the discovery of several compounds that exhibited efficacy when administered orally in murine pyelonephritis and pneumonia models.

Process research and development of the first fully synthetic broad spectrum 7-fluorotetracycline in clinical development is described. The process utilizes two key intermediates in a convergent approach. The key transformation is a Michael–Dieckmann reaction between a suitable substituted aromatic moiety and a key cyclohexenone derivative. Subsequent deprotection and acylation provide the desired active pharmaceutical ingredient in good overall yield.

A novel series of fully synthetic 8-azatetracyclines was prepared and evaluated for antibacterial activity. Compounds were identified that overcome both efflux (tet(K)) and ribosomal protection (tet(M)) tetracycline resistance mechanisms and are active against Gram-positive and Gram-negative organisms. Two compounds were identified that exhibit comparable efficacy to marketed tetracyclines in in vivo models of bacterial infection.

A series of novel hexacyclic tetracycline analogues (“hexacyclines”) was designed, synthesized, and evaluated for antibacterial activity against a wide range of clinically important bacteria isolates, including multidrug-resistant, Gram-negative pathogens. Valuable structure–activity relationships were identified, and several hexacyclines displayed potent, broad spectrum antibacterial activity, including promising anti-Pseudomonas aeruginosa activity in vitro and in vivo.

An asymmetric hydrogenation process of 3-substituted pyridine derivatives has been developed with the use of a Rh-TangPhos complex as the catalyst. The whole process consists of an efficient partial hydrogenation of nicotinate and a subsequent highly enantioselective, Rh-catalyzed, homogeneous hydrogenation. A series of chiral nipecotic acid derivatives have been synthesized. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)

Salvinorin A is the most potent naturally occurring opioid agonist with a high selectivity and affinity for kappa-opioid receptor. To explore its structure-activity relationships, modifications at the C(4) position have been studied and a series of salvinorin A derivatives were prepared. These C(4)-modified salvinorin A analogues were screened for binding and functional activities at the human kappa-opioid receptor and several potent new agonists have been identified.

Salvinorin A is the most potent naturally occurring opioid agonist yet discovered with high selectivity and affinity for κ-opioid receptor. To explore its structure and activity relationships, a series of salvinorin A derivatives modified at the C(2) position were prepared and studied. These salvinorin A derivatives were screened for binding and functional activities at the human κ-opioid receptor. Compound 4, containing a methoxymethyl group at the 2-position, was a full κ-agonist with an EC50 value at 0.6 nM, which is about 7 times more potent than salvinorin A.

A kinetic resolution process of Rh-catalyzed intramolecular Alder-ene reaction is described along with the studies of the substrate scope and stereochemistry of this remarkably efficient process. 3,4,5-Trisubstituted γ-lactones were synthesized in high enantioselectivity (>99% ee) and efficiency. The formal asymmetric syntheses of (−)-blastmycinolactol and (+)-blastmycinone, degradation products of the macrocyclic dilactone (+)-antimycin, were reported to address the applications of this methodology.

Utilizing a fully synthetic route to tetracycline analogues, the C-9 side-chain of the fluorocyclines was optimized for both antibacterial activity and oral efficacy. Compounds were identified that overcome both efflux (tet(K), tet(A)) and ribosomal protection (tet(M)) tetracycline-resistance mechanisms and are active against Gram-positive and Gram-negative organisms. A murine systemic infection model was used as an oral efficacy screen to rapidly identify compounds with oral bioavailability. Two compounds were identified that exhibit both oral bioavailability in rat and clinically relevant bacterial susceptibility profiles against major respiratory pathogens. One compound demonstrated oral efficacy in rodent lung infection models that was comparable to marketed antibacterial agents.

A highly enantioselective Rh(I)-catalyzed intramolecular Alder ene reaction has been developed. The desired products, 3-vinyl, vinyl acetate, and vinyl ether-substitued α-methylene-γ-butyrolactones were formed in high yields. Aldehydes were produced with the formation of γ-lactones when alcohols were substituted at allylic position in the substrates. All reactions with listed substrates proceeded in over 99% ee. A formal synthesis of (+)-pilocarpine is an excellent example to demonstrate the synthetic utility of this methodology.

A catalyst system, [Rh(COD)Cl]2–BINAP–AgSbF6, has been developed as a second-generation catalyst for the cycloisomerization of 1,6-enynes tethered by carbon chains. Cyclopentanes and cyclopentanones, which can contain functional groups, such as the 1,4-dienes, vinyl ether, aldehyde etc., were obtained from readily available starting materials in high yields and selectivities. Both regioselectivities and enantioselectivities are excellent: only 1,4-dienes were observed and in over 99% ee.

A catalyst system, [Rh(COD)Cl](2)-BINAP-AgSbF(6), has been developed as a second-generation catalyst for the cycloisomerization of 1,6-enynes tethered by carbon chains. Cyclopentanes and cyclopentanones, which can contain functional groups, such as the 1,4-dienes, vinyl ether, aldehyde etc., were obtained from readily available starting materials in high yields and selectivities. Both regioselectivities and enantioselectivities are excellent: only 1,4-dienes were observed and in over 99% ee.

An asymmetric hydrogenation process of 3-substituted pyridine derivatives has been developed with the use of a Rh-TangPhos complex as the catalyst. The whole process consists of an efficient partial hydrogenation of nicotinate and a subsequent highly enantioselective, Rh-catalyzed, homogeneous hydrogenation. A series of chiral nipecotic acid derivatives have been synthesized. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)

Aryl C-glycosides are stable analogs of the corresponding O-glycosides. Because of their favorable pharmacological profiles attributed primarily to the C-glycosyl moiety, aryl C-glycosides have gained increasing popularity as drug candidates. In this review we focus on the synthesis of aryl C-glycosides including puerarin and kendomycin. This review is organized based on the type of chemistry used in the assembly of the C-glycosides with the following sub-sections: electrophilic reaction, cross-coupling reaction, free radical reaction, cyclization, intramolecular O-C rearrangement, umpolung, and miscellaneous reactions.

Salvinorin A, a compound isolated from the plant Salvia divinorum, is a potent and highly selective agonist for the κ opioid receptor. For exploration of its structure and activity relationships, further modifications, such as reduction at the C(4) position, have been studied and a series of salvinorin A derivatives were prepared. These C(4)-modified salvinorin A analogues were screened for binding and functional activities at the human κ-opioid receptor and several new full agonists have been identified.

A new BIPHEP-type ligand with phenyl groups at the 3,3′-positions, o -Ph-MeO-BIPHEP 3 was prepared. This ligand afforded excellent enantioselectivities when used in the Rh-catalyzed asymmetric hydrogenation of α-dehydroamino acid derivatives. The strong influence of o -phenyl groups of the ligand on the enantioselectivities of the reaction has been demonstrated by a comparison with its parent ligand MeO-BIPHEP.

A new type of alpha-phthalimide ketones was hydrogenated in excellent enantioselectivity by using a Ru-(C3-TunePhos) complex as the catalyst. Up to 10 000 turnovers have been achieved in more than 99% ee in the hydrogenation reaction. A dynamic kinetic resolution study for the synthesis of threonine was performed, and high anti selectivity (97:3) was observed for the first time. An efficient method to synthesize enantiomerically pure amino alcohols has been developed.

The rising demand for chiral raw materials, intermediates, and active ingredients in pharmaceuticals, agrochemicals, food additives, and fragrances provides the impetus for rapid developments in chiral technology.[1] It remains a huge challenge for organic chemists to develop highly enantioselective reactions for the preparation of enantiomerically pure compounds in a cost-effective manner. Lactams are a versatile motif in organic chemistry and when functionalized, lactams often either show biological activity themselves, or are important building blocks for biologically active molecules such as (þ)-a-allokainic acid, (þ)-a-kainic acid,[2] acromelic

Alder±ene reactions are a powerful way to construct carbon±carbon bonds. The intramolecular version of these reactions can provide efficient routes to produce a variety of heterocyclic and carbocyclic compounds.[1] Since the thermal Alder±ene reaction requires high temperature, it has found limited applications in organic syntheses. In contrast, transition-metal-catalyzed Alder±ene reactions can be performed under mild conditions and therefore are widely applied to organic syntheses.[2] However, the enantioselective processes of metal-catalyzed Alder±ene reactions are relatively unexplored and the development of highly efficient catalysts still remains a great challenge.[3] Recently, we have developed Rhcatalyzed intramolecular Alder±ene reactions of enynes using a [{Rh(diphos)Cl}2] precursor.[4] Enantioselectivities between 65±98% ee were obtained by using 1,2-bis(phospholano)benzene (Duphos), (2R,2’R)-bis(diphenylphosphanyl)-(1R,1’R)dicyclopentane (BICP), or the related (2R,2’R)-bis(diphenylphosphinite)-(1R,1’R)-dicyclopentane (BICPO) as chiral ligands.[4a] Herein, we report a significant improvement of the catalytic system for these reactions. The new catalysts are prepared in situ by simply mixing a commercially available metal precursor and a ligand. Over 99% ee has been achieved for a number of substrates. To achieve high enantioselectivities for Rh-catalyzed Alder±ene reactions, we have screened a number of chiral phosphane ligands. The enyne 1a was chosen as a standard substrate to optimize the reaction conditions and the results are given in Table 1. In the absence of phosphane ligand, [{Rh(cod)Cl}2] was an ineffective catalytic precursor at either room temperature or 65 8C (Table 1, entries 1 and 2). However, [{Rh(nbd)Cl}2] (nbd1⁄4 norbornadiene) can be used as a catalyst precursor at 65 8C (Table 1, entry 6). Using the CnTunaphos ligands developed by our group,[5] high efficiency was observed. When rac-C4-Tunaphos was used as the ligand in the presence of [{Rh(cod)Cl}2] and AgSbF6, high conversion (100%) and a high yield (98%) were obtained at room temperature within 20 min (Table 1, entry 9). Control experiments indicated that there were big differences between this new catalytic system and the earlier protocol developed by us using [{Rh(diphosphane)Cl}2] as catalytic precursor. We previously reported that [{Rh(BINAP)Cl}2] (BINAP1⁄4 2,2’COMMUNICATIONS

A highly enantioselective Rh(I)-catalyzed intramolecular Alder ene reaction has been developed. The desired products, 3-vinyl, vinyl acetate, and vinyl ether-substitued alpha-methylene-gamma-butyrolactones were formed in high yields. Aldehydes were produced with the formation of gamma-lactones when alcohols were substituted at allylic position in the substrates. All reactions with listed substrates proceeded in over 99% ee. A formal synthesis of (+)-pilocarpine is an excellent example to demonstrate the synthetic utility of this methodology.