Synthesis Development of the Selective Estrogen Receptor Degrader (SERD) LSZ102 from a Suzuki Coupling to a C–H Activation Strategy

Preparative Scale Applications of C-H Activation in Medicinal Chemistry

C-H activation is an attractive methodology to increase molecular complexity without requiring substrate prefunctionalization. In contrast to well-established cross-coupling methods, C-H activation is less explored on large scales and its use in the production of pharmaceuticals faces substantial hurdles. However, the inherent advantages, such as shorter synthetic routes and simpler starting materials, motivate medicinal chemists and process chemists to overcome these challenges, and exploit C-H activation steps for the synthesis of pharmaceutically relevant compounds. In this review, we will cover examples of drugs/drug candidates where C-H activation has been implemented on a preparative synthetic scale (range between 355 mg and 130 kg). The optimization processes will be described, and each example will be examined in terms of its advantages and disadvantages, providing the reader with an in-depth understanding of the challenges and potential of C-H activation methodologies in the production of pharmaceuticals.

Targeting the Estrogen Receptor for the Treatment of Breast Cancer: Recent Advances and Challenges

Estrogen receptor alpha (ERα) is a well-established therapeutic target for the treatment of ER-positive (ER+) breast cancers. Despite the tremendous successes achieved with tamoxifen, a selective ER modulator, and aromatase inhibitors (AIs), resistance to these therapies is a major clinical problem. Therefore, induced protein degradation and covalent inhibition have been pursued as new therapeutic approaches to target ERα. This Perspective summarizes recent progress in the discovery and development of oral selective ER degraders (SERDs), complete estrogen receptor antagonists (CERANs), selective estrogen receptor covalent antagonists (SERCAs), and proteolysis targeting chimera (PROTAC) ER degraders. We focus on those compounds which have been advanced into clinical development.

Discovery of Thieno[2,3-e]indazole Derivatives as Novel Oral Selective Estrogen Receptor Degraders with Highly Improved Antitumor Effect and Favorable Druggability

Endocrine therapies in the treatment of early and metastatic estrogen receptor α positive (ERα+) breast cancer (BC) are greatly limited by de novo and acquired resistance. Selective estrogen receptor degraders (SERDs) like fulvestrant provide new strategies for endocrine therapy combinations due to unique mechanisms. Herein, we disclose our structure-based optimization of LSZ102 by replacing 6-hydroxybenzothiophene with 6H-thieno[2,3-e]indazole. Subsequent acrylic acid degron modifications led us to identify compound 40 as the preferred candidate. In general, compound 40 showed much better pharmacological profiles than the lead LSZ102, exhibiting growth inhibition of wild-type or tamoxifen-resistant MCF-7 cells, potent ERα degradation, together with superior pharmacokinetic properties, directional target tissue distribution including the brain, and robust antitumor efficacy in the mice breast cancer xenograft model. Currently, 40 is being evaluated in preclinical trials.

Recent Applications of Pd-Catalyzed Suzuki–Miyaura and Buchwald–Hartwig Couplings in Pharmaceutical Process Chemistry

Cross-coupling reactions have changed the way complex molecules are synthesized. In particular, Suzuki–Miyaura and Buchwald–Hartwig amination reactions have given opportunities to elegantly make pharmaceutical ingredients. Indeed, these reactions are at the forefront of both the stages of drug development, medicinal chemistry, and process chemistry. On the one hand, these reactions have given medicinal chemists a resource to derivatize the core compound to arrive at scaffold rapidly. On the other hand, these cross couplings have offered the process chemists a smart tool to synthesize the development candidates safely, quickly, and efficiently. Generally, the application of cross-coupling reactions is broad. This review will specifically focus on their real (pharma) world applications in large-scale synthesis appearing in the last three years.

Scalable Approach to Fluorinated Heterocycles with Sulfur Tetrafluoride (SF4)

A general approach to fluorinated (hetero)aromatic derivatives is elaborated. The key reaction is a deoxofluorination of substituted acetophenones with sulfur tetrafluoride (SF₄). In contrast to previous deoxofluorination methods, this transformation is fast, scalable (up to 70 g), and high-yielding. More than 100 novel or previously hardly accessible fluorinated heterocycles, interesting for medicinal chemistry and agrochemistry, were synthesized.