Stephen Fletcher

Jun 27, 2024 | digitalcommons.library.tmc.edu | Laura Cunningham |Sourabh Mishra |Leon Matthews |Stephen Fletcher

We report a general, catalyst-controlled route to prostaglandin F2α and its analogues. The approach uses a Rh-catalyzed dynamic kinetic asymmetric Suzuki–Miyaura coupling reaction between a racemic bicyclic allyl chloride and alkenyl boronic esters bearing chiral alcohols to give cyclopentyl intermediates bearing 3 contiguous stereocenters.

Jun 27, 2024 | digitalcommons.library.tmc.edu | Laura Cunningham |Stephen Fletcher |Mireia Sidera |Mireia Sidera Portela

Csp2–Csp2 Suzuki–Miyaura couplings (SMCs) are ubiquitous in the synthesis of small molecules, but analogous Csp2–Csp3 bond-forming SMCs are rare, especially asymmetric variants. Recently, we developed a series of Rh-catalyzed couplings between racemic sp3-hybridized allyl chlorides and heteroaryl boronic acids. Here, we demonstrate that these catalytic asymmetric reactions can be scaled-up to give over 100 g of a product.

Jun 27, 2024 | digitalcommons.library.tmc.edu | Yan Zhang |F Wieland Goetzke |Kirsten Christensen |Stephen Fletcher

Tropane derivatives are extensively used in medicine, but catalytic asymmetric methods for their synthesis are underexplored. Here, we report Rh-catalyzed asymmetric Suzuki–Miyaura-type cross-coupling reactions between a racemic N-Boc-nortropane-derived allylic chloride and (hetero)aryl boronic esters. The reaction proceeds via an unexpected kinetic resolution, and the resolved enantiopure allyl chloride can undergo highly enantiospecific reactions with N-, O-, and S-containing nucleophiles.

Jun 27, 2024 | digitalcommons.library.tmc.edu | Lauren Salisbury |Stephen Fletcher |Jeanette E Stok |Luke R Churchman

Cholesterol is the precursor of bioactive plant metabolites such as steroidal saponins. An Australian plant, Dioscorea transversa, produces only two steroidal saponins: 1β-hydroxyprotoneogracillin and protoneogracillin. Here, we used D. transversa as a model in which to elucidate the biosynthetic pathway to cholesterol, a precursor to these compounds. Preliminary transcriptomes of D. transversa rhizome and leaves were constructed, annotated, and analyzed.

Jun 27, 2024 | digitalcommons.library.tmc.edu | Laura Cunningham |Sourabh Mishra |Leon Matthews |Stephen Fletcher

We report a general, catalyst-controlled route to prostaglandin F2α and its analogues. The approach uses a Rh-catalyzed dynamic kinetic asymmetric Suzuki–Miyaura coupling reaction between a racemic bicyclic allyl chloride and alkenyl boronic esters bearing chiral alcohols to give cyclopentyl intermediates bearing 3 contiguous stereocenters.