Enantio- and Diastereoselective Total Synthesis of Belzutifan Enabled by Rh-Catalyzed Hydrogenation.

Herein, we report a nine-step synthesis of belzutifan enabled by a novel Rh-catalyzed asymmetric hydrogenation to install the contiguous fluorinated stereocenters with high enantioselectivity. Moreover, the final ketone reduction in the synthesis proceeds with high diastereoselectivity, leading to the expedient assembly of the stereotriad. In contrast to the original 16-step synthesis, this route avoids a lengthy bromination-oxidation sequence and introduces the sulfone functionality via nucleophilic aromatic substitution, obviating the need for transition metal catalysis.

Engineering Hydroxylase Activity, Selectivity, and Stability for a Scalable Concise Synthesis of a Key Intermediate to Belzutifan.

Biocatalytic oxidations are an emerging technology for selective C-H bond activation. While promising for a range of selective oxidations, practical use of enzymes catalyzing aerobic hydroxylation is presently limited by their substrate scope and stability under industrially relevant conditions. Here, we report the engineering and practical application of a non-heme iron and α-ketoglutarate-dependent dioxygenase for the direct stereo- and regio-selective hydroxylation of a non-native fluoroindanone en route to the oncology treatment belzutifan, replacing a five-step chemical synthesis with a direct enantioselective hydroxylation.

Overcoming Product Inhibition in a Nucleophilic Aromatic Substitution Reaction.

The development of a nucleophilic aromatic substitution (SAr) reaction for the synthesis of belzutifan and related analogues is disclosed. This classical transformation suffered from reaction stalling, despite prolonged reaction times. Through experimental and mechanistic studies, product inhibition was revealed and rationalized.

Hydrogenation catalyst generates cyclic peptide stereocentres in sequence.

Molecular recognition plays a key role in enzyme-substrate specificity, the regulation of genes, and the treatment of diseases. Inspired by the power of molecular recognition in enzymatic processes, we sought to exploit its use in organic synthesis. Here we demonstrate how a synthetic rhodium-based catalyst can selectively bind a dehydroamino acid residue to initiate a sequential and stereoselective synthesis of cyclic peptides.

Highly Stereoselective Synthesis of Tetrasubstituted Acyclic All-Carbon Olefins via Enol Tosylation and Suzuki-Miyaura Coupling.

A highly stereocontrolled synthesis of tetrasubstituted acyclic all-carbon olefins has been developed via a stereoselective enolization and tosylate formation, followed by a palladium-catalyzed Suzuki-Miyaura cross-coupling of the tosylates and pinacol boronic esters in the presence of a Pd(OAc)/RuPhos catalytic system. Both the enol tosylation and Suzuki-Miyaura coupling reactions tolerate an array of electronically and sterically diverse substituents and generate high yield and stereoselectivity of the olefin products. Judicious choice of substrate and coupling partner provides access to either the E- or Z-olefin with excellent yield and stereochemical fidelity.

Cyclizing Pentapeptides: Mechanism and Application of Dehydrophenylalanine as a Traceless Turn-Inducer.

Dehydrophenylalanine is used as a traceless turn-inducer in the total synthesis of dichotomin E. Macrocyclization of the monomer is achieved in high yields and selectivity over cyclodimerization under conditions 100 times more concentrated than previously achieved. The enamide facilitates ring closing, and Rh-catalyzed hydrogenation of the unsaturated cyclic peptide results in selective formation of the natural product or its epimer, depending on our choice of phosphine ligand.

Rh(I)-catalyzed intermolecular hydroacylation: enantioselective cross-coupling of aldehydes and ketoamides.

Under Rh(I) catalysis, α-ketoamides undergo intermolecular hydroacylation with aliphatic aldehydes. A newly designed Josiphos ligand enables access to α-acyloxyamides with high atom-economy and enantioselectivity. On the basis of mechanistic and kinetic studies, we propose a pathway in which rhodium plays a dual role in activating the aldehyde for cross-coupling.

Recognition and site-selective transformation of monosaccharides by using copper(II) catalysis.

We demonstrate copper(II)-catalyzed acylation and tosylation of monosaccharides. Various carbohydrate derivatives, including glucopyranosides and ribofuranosides, are obtained in high yields and regioselectivities. Using this versatile strategy, the site of acylation can be switched by choice of ligand.