Synthesis of tricyclic and tetracyclic sultones by Pd-catalyzed intramolecular cyclization

The Synthesis and Reactivity of Naphthoquinonynes

The first systematic exploration of the synthesis and reactivity of naphthoquinonynes is described. Routes to two regioisomeric Kobayashi-type naphthoquinonyne precursors have been developed, and the reactivity of the ensuing 6,7- and 5,6-aryne intermediates has been investigated. Remarkably, these studies have revealed that a broad range of cycloadditions, nucleophile additions and difunctionalizations can be achieved while maintaining the integrity of the highly sensitive quinone unit. The methodologies offer a powerful diversity oriented approach to C6 and C7 functionalized naphthoquinones, which are typically challenging to access. From a reactivity viewpoint, the study is significant because it demonstrates that aryne-based functionalizations can be utilized strategically in the presence of highly reactive and directly competing functionality.

Progress in the synthesis of δ-sultones

Abstract

Sultones, the cyclic esters of hydroxyl sulfonic acids, are a fascinating class of heterocycles and the recent years have witnessed an increasing interest in these molecules, especially in six-ring δ-sultones. The importance of these compounds is either because of their biological properties themselves or due to their versatility as intermediates in more complex target syntheses. Accordingly, the development of new synthesis methods to access δ-sultones is an important and rewarding task which we wish to highlight in this review.

Graphical abstract

1,7-Naphthodiyne: a new platform for the synthesis of novel, sterically congested PAHs

The synthesis of an efficient precursor of the novel 1,7-naphthodiyne synthon is reported.

Synthesis and anti-BVDV activity of novel δ-sultones in vitro: implications for HCV therapies

In this study we report the synthesis and activity against bovine viral diarrhea virus (BVDV) of a novel series of bicycle δ-sultones containing γ-lactones. BVDV is responsible for major losses in cattle. Some of the synthesized δ-sultones showed pronounced anti-BVDV activity with EC50 values of 0.12-1.0μM and no significant cytotoxicity. Among them, the ortho bromosubstituted derivative 4f (EC50=0.12μM) showed better antiviral activity than other derivatives and was 10 fold more that of than positive control ribavirin (EC50=1.3μM). BVDV is also considered to be a valuable surrogate for the hepatitis C virus (HCV) in antiviral drug studies. The above results provided a novel candidate for the development of anti-HCV agents.