We report a Rh-catalyst for accessing olefins from primary alcohols by a C-C bond cleavage that results in dehomologation. This functional group interconversion proceeds by an oxidation-dehydroformylation enabled by N, N-dimethylacrylamide as a sacrificial acceptor of hydrogen gas. Alcohols with diverse functionality and structure undergo oxidative dehydroxymethylation to access the corresponding olefins. Our catalyst protocol enables a two-step semisynthesis of (+)-yohimbenone and dehomologation of feedstock olefins.

We report a Rh-catalyzed hydroamination of 1,3-dienes to generate homoallylic amines. Our work showcases the first case of anti-Markovnikov selectivity in the intermolecular coupling of amines and 1,3-dienes. By tuning the ligand properties and Brønsted acid additive, we find that a combination of rac-BINAP and mandelic acid is critical for achieving anti-Markovnikov selectivity.

Nickel-catalyzed enantioselective cross- couplings between symmetric cyclic sulfates and aromatic Grignard reagents are described. These reactions are effective with a broad range of substituted cyclic sulfates and deliver products with asymmetric tertiary carbon centers. Mechanistic experiments point to a stereoinvertive SN2-like oxidative addition of a nickel complex to the electrophilic substrate.

In this article, we advance Rh-catalyzed hydrothiolation through the divergent reactivity of cyclopropenes. Cyclopropenes undergo hydrothiolation to provide cyclopropyl sulfides or allylic sulfides. The choice of bisphosphine ligand dictates whether the pathway involves ring-retention or ring-opening. Mechanistic studies reveal the origin for this switchable selectivity. Our results suggest the two pathways share a common cyclopropyl-Rh(III) intermediate. Electron-rich Josiphos ligands promote direct reductive elimination from this intermediate to afford cyclopropyl sulfides in high enantio-and diastereoselectivities. Alternatively, atropisomeric ligands (such as DTBM-BINAP) enable ring-opening from the cyclopropyl-Rh(III) intermediate to generate allylic sulfides with high enantio-and regiocontrol.

We present two simple classroom exercises designed to explain challenging concepts in conformation for students beginning organic chemistry. These macroscopic demonstrations serve as analogies to bridge students' understanding of flat twodimensional drawings to real three-dimensional molecules. In the first demonstration, an apple is drawn from its familiar side-on perspective, followed by a "Newman Projection" of an apple, an unusual drawing from the top-down perspective. We show how the two drawings differ drastically despite depicting the same apple. With this definition in mind, they are then asked to draw an alkane from its more familiar side-on perspective, followed by a Newman projection down a central carbon-carbon bond. By comparing apples to alkanes, we demonstrate that a "Newman projection" is simply a drawing made from a different perspective, whether it be down an apple core or along a carbon-carbon bond. In the second activity, student volunteers perform jumping jacks in the front of the classroom. Snapshots of the students illustrate that people can adopt different conformations just as alkanes do, and that these conformations differ in energy. A survey of the class revealed that 95% found these demonstrations helped clarify their understanding of Newman projections and conformational analysis.