Discovery and Optimization of Potent, Selective, and Brain-Penetrant 1-Heteroaryl-1-Indazole LRRK2 Kinase Inhibitors for the Treatment of Parkinson's Disease.

Inhibition of leucine-rich repeat kinase 2 (LRRK2) kinase activity represents a genetically supported, chemically tractable, and potentially disease-modifying mechanism to treat Parkinson's disease. Herein, we describe the optimization of a novel series of potent, selective, central nervous system (CNS)-penetrant 1-heteroaryl-1-indazole type I (ATP competitive) LRRK2 inhibitors. Type I ATP-competitive kinase physicochemical properties were integrated with CNS drug-like properties through a combination of structure-based drug design and parallel medicinal chemistry enabled by sp-sp cross-coupling technologies.

Discovery of Diaminopyrimidine Carboxamide HPK1 Inhibitors as Preclinical Immunotherapy Tool Compounds.

Hematopoietic progenitor kinase 1 (HPK1), a serine/threonine kinase, is a negative immune regulator of T cell receptor (TCR) and B cell signaling that is primarily expressed in hematopoietic cells. Accordingly, it has been reported that HPK1 loss-of-function in HPK1 kinase-dead syngeneic mouse models shows enhanced T cell signaling and cytokine production as well as tumor growth inhibition , supporting its value as an immunotherapeutic target. Herein, we present the structurally enabled discovery of novel, potent, and selective diaminopyrimidine carboxamide HPK1 inhibitors.

Development of a Flexible and Robust Synthesis of Tetrahydrofuro[3,4-]furan Nucleoside Analogues.

In the context of a PRMT5 inhibitor program, we describe our efforts to develop a flexible and robust strategy to access tetrahydrofuro[3,4-]furan nucleoside analogues. Ultimately, it was found that a Wolfe type carboetherification from an alkenol derived from d-glucofuranose diacetonide was capable of furnishing the B-ring and installing the desired heteroaryl group in a single step. Using this approach, key intermediate was delivered on a gram scale in a 62% yield and 9.

Lessons from the synthetic chemist nature.

This conceptual review examines the ideal multistep synthesis from the perspective of nature. We suggest that besides step- and redox economies, one other key to efficiency is steady state processing with intermediates that are immediately transformed to the next intermediate when formed. We discuss four of nature's strategies (multicatalysis, domino reactions, iteration and compartmentation) that commonly proceed via short-lived intermediates and show that these strategies are also part of the chemist's portfolio.

Development of an intramolecular aryne ene reaction and application to the formal synthesis of (±)-crinine.

A general and high yielding annulation strategy for the synthesis of various carbo- and heterocycles, based on an intramolecular aryne ene reaction is described. It was found that the geometry of the olefin is crucial to the success of the reaction, with exclusive migration of the trans-allylic-H taking place. Furthermore, the electronic nature of the aryne was found to be important to the success of the reaction.

Intramolecular aryne-ene reaction: synthetic and mechanistic studies.

Although the chemistry of arynes is well developed, some challenges still remain. The ene reaction of arynes has not gained widespread use in synthesis as a result of poor yields and selectivity. A general, high yielding and selective intramolecular aryne-ene reaction is described providing various benzofused carbo- and heterocycles.

Formal synthesis of nitidine and NK109 via palladium-catalyzed domino direct arylation/N-arylation of aryl triflates.

The use of aryl triflates as reaction partners in a palladium-catalyzed domino direct arylation/N-arylation provides a great advantage due to the availability of starting materials. Furthermore, it allows expedient access to biologically interesting benzo[c]phenanthridine alkaloids.

Palladium-catalyzed reductive ortho-arylation: evidence for the decomposition of 1,2-dimethoxyethane and subsequent arylpalladium(II) reduction.

A palladium-catalyzed crossed biaryl coupling/reduction sequence enables the formation of meta-substituted biaryls via solvent-mediated arylpalladium(II) reduction. Isotope labeling studies determined that the decomposition of 1,2-dimethoxyethane (DME) is indeed involved in the reductive process.

Exploiting the chemistry of strained rings: synthesis of indoles via domino reaction of aryl iodides with 2H-azirines.

The highly strained 2H-azirine ring system has been the source of considerable theoretical and synthetic work. The reaction of these strained heterocycles with transition metals has been documented to give rise to ring opening and subsequent formation of varied heterocycles. An interesting domino reaction is described wherein the strained bicyclic alkene, norbornene, mediates the reaction of 2H-azirines with aryl iodides under palladium catalysis to provide indole or polycyclic dihydroimidazole heterocycles.

Exploiting the divergent reactivity of aryl-palladium intermediates for the rapid assembly of fluorene and phenanthrene derivatives.

They all fall down: The value of domino processes can be greatly enhanced when the possibility exists for one to selectively diverge from a common intermediate. In preliminary studies the dual reactivity of aryl-palladium intermediates is exploited. A diverse array of fluorene and phenanthrene derivatives were synthesized in a rapid and efficient manner (see scheme).