Rhodium(II)-Catalyzed Alkyne Amination of Homopropargylic Sulfamate Esters: Stereoselective Synthesis of Functionalized Norcaradienes by Arene Cyclopropanation

Abstract

A rhodium(II) catalyzed nitrene-alkyne cycloaddition of stereochemically well-defined homopropargylic ethers is followed by arene cyclopropanation to afford unique tetracyclic norcaradiene products bearing a cyclic sulfamate. Products from the arene cyclopropanation (Buchner reaction) can be converted to fused cycloheptatrienes via a ring enlarging electrocyclization after nucleophilic ring opening of the cyclic sulfamate ester.

Catalytic Nitrene Transfer To Alkynes: A Novel and Versatile Route for the Synthesis of Sulfinamides and Isothiazoles

“…Because of this, there are very few examples (Scheme ) of catalytic reactions involving the alkyne and nitrene groups. Blakey and Panek independently described the intramolecular nitrene attack onto a triple carbon–carbon bond (Scheme a, b) in the presence of a rhodium‐based catalyst. The intermolecular reaction has only been described by Saito et al., albeit in the presence of nitrile as a third partner, leading to imidazoles (Scheme c).…”

The chemistry of the carbon-transition metal double and triple bond: Annual survey covering the year 2014

“…1083) from alkyne sulfamates (e.g. 1079) under conditions that generate nitrenes [1126]. The carbene complex forms from reaction of the nitrene complex (e.g.…”

Synthesis of Acyclic and Cyclic Sulfamates: A Review

“…A new metallonitrene/alkyne metathesis reaction took place by the oxidative cyclization of sulfamates 116 with dirhodium(II) tetracarboxylate salts as the catalyst, which gave a bicyclic system 117 by formation of new C-N, C-O, and C-C bonds (Scheme 36). 133,134 The reaction was efficiently catalyzed by range of dirhodium(II) tetracarboxylate salts in a variety of common solvents. This cascade reaction was carried by a (2+2) metathesis mechanism from a remarkably simple starting material.…”