Rh(iii)-Catalyzed C–H allylation/annulative Markovnikov addition with 5-methylene-1,3-dioxan-2-one: formation of isoquinolinones containing a C3 quaternary centre

Abstract

The Rh(III)-catalyzed synthesis of isoquinolinones containing C3 quaternary centre via a tandem C-H allylation/annulative Markovinkov addition reaction has been achieved. This method employing a single Rh(III) complex as the catalyst...

A new type of δ-vinylvalerolactone for palladium-catalyzed cycloaddition: synthesis of nine-membered heterocycles

“…In these cycloaddition reactions, the precursors for the formation of π-allylpalladium zwitterionic intermediates play a key role in the cycloaddition reactions, influencing the reactivity, cycloaddition types and structure of the cycloadducts. A variety of precursors with diverse structures such as vinylethylene carbonates, 2 vinyloxazolidinones, 3 vinyl benzoxazinanones, 4 γ-methylidene-δ-valerolactones, 5 2-methylidenetrimethylene carbonates, 6 vinyl oxazinanones, 7 vinylpropylene carbonates, 8 and acyclic allylic carbonates, 9 have been used to realize numerous reactions for accessing diversified carbocyclic, oxygen- and nitrogen-containing cyclic compounds (Scheme 1a). These precursors often serve as three-, four-, and five-membered synthons and only very limited precursors could work as a six-membered synthon to perform cycloaddition reactions for the synthesis of medium-sized ring compounds.…”

Tandem annulation and dipolar cycloaddition of azomethine imines in catalytic C(sp2)–H functionalization

“…Cyclic carbonates with exo-olefin moieties, such as 2-methylidenetrimethylene carbonate, have been intensively used in catalytic C-H allylation reactions. [65][66][67][68][69] In 2022, Kim's group highlighted the ruthenium(II)-catalyzed tandem C-H allylation and intramolecular dipolar cycloaddition between azomethine imines and 2-methylidenetrimethylene carbonate (Scheme 30). 70 A wide range of azomethine imines were screened for the coupling reaction.…”

In Situ Generation of Propadiene from 1-Cyclopropyl-1-nitrosourea for Rh(III)-Catalyzed Synthesis of Isoquinolinones and Pyridinones Containing a Methylene Functionality

“…In addition, Rh­(III)-catalyzed approaches involving the annulation of allenes were also available to deliver heterocycles containing CC double bonds, which were pioneered by Glorius, by Ma, and later by Lin and co-workers and Shi and co-workers (Figure C). These precedents as well as our continued interest in the development of transition metal-catalyzed methodologies to synthesize valuable heterocycles prompted us to anticipate the viability of using propadiene to construct useful methylene-functionalized isoquinolinones and pyridinones using the N–O bond as the directing group and internal oxidant …”