Evolution of a Chemical Strategy Toward the Synthesis of Unsymmetrically Oxidized Nuphar Alkaloids

Here we describe the frustrations, joys, and unexpected turns experienced in our journey toward a successful strategy directed at the total synthesis of unsymmetrically oxidized Nuphar thioalkaloids. While many adjustments were made to our initial synthesis plan, our general approach to the construction of the central bis(spirothiolane) moiety remained unchanged. Specifically, each iteration of our synthesis design involved the formation of the thiaspirane motif through the stereodivergent coupling of a thietane with a metal carbenoid, followed by a Stevens-type rearrangement of the resulting sulfonium ylide.1 Introduction2 First-Generation Strategy3 Second-Generation Strategy4 Third-Generation Strategy5 Conclusion

Catalyst-dependent selectivity in sulfonium ylide cycloisomerization reactions

An unusual example of π-acid catalyst-dependent selectivity in the cycloisomerization of alkene-tethered sulfonium ylides affords cyclopropanes or dihydrofurans with excellent control of chemoselectivity.

Aqueous hemin catalyzed sulfonium ylide formation and subsequent [2,3]-sigmatropic rearrangements

A mild and efficient strategy for the Doyle–Kirmse reaction is established and an unprecedented cascade C–H insertion is reported.