Crossing the Ring: A Journey of the Nitroso-ene Reaction

Abstract

Recent progress in the nitroso-ene reaction indicates the potentially rich reactivity of the nitroso species. In this study, we highlight the synthetic efforts towards the construction of the aza-spirocyclic or aza-bridged ring embedded in biologically significant alkaloids via the proposed approach. Our endeavors along this direction are exemplified in the formal synthesis of (±)-cephalotaxine and the total synthesis of (-)-hosieine A. 1 Introduction 2 Aza-Spirocyclane: A Formal Synthesis of (±)-Cephalotaxine 3Method Development 4Aza-Bridge Ring: A Total Synthesis of (-)-Hosieine A 5 Epilogue

Nickel‐Catalyzed Tunable Enantioconvergence and Kinetic Resolution in the Coupling of Tertiary Cyclobutenols with Arylboroxines

“…In addition to ring‐opening or ring‐contraction transformations, we further carried out olefin functionalization of the product S ‐ 3 a by keeping the strained ring untouched. For example, treatment of S ‐ 3 a with Et 3 N⋅3 HF and NIS ( N ‐iodosuccinimide) can deliver the corresponding fluoro‐ and iodo‐difunctionalized product 5 d in 54 % yield, [27e] and hydroboration‐oxidation of S ‐ 3 a produced the corresponding alcohols 5 e and 5 f in 37 % and 31 % yield respectively [27f] (The relative configurations were confirmed by NOESY experiments shown in the Supporting Information).…”

Synform Issue 2017/5

“…5 We also reported a Rucatalyzed C-H silylation of heteroarenes that requires no protecting groups for alkyl or aryl amine substituents, and demonstrates for the first time that undirected C-H silylation is possible under Ru catalysis (Scheme 1c). 6 Additionally, we found that electron rich Ru centers are able to cleave the indole C4-H bond, which was previously the exclusive province of strongly electrophilic metals. We hope to build on these discoveries, of course.…”

“…Based on Matteson's work 6 on chloromethyllithium in the mid-1980s, the group tried to use the sulfonimidates as electrophiles in Barbier-type reactions with chloroiodomethane and n-BuLi (Scheme 2).…”