Gold-Catalyzed [2,3]-Sigmatropic Rearrangement: Reaction of Aryl Allyl Alcohols with Diazo Compounds

Abstract

A gold-catalyzed [2,3]-sigmatropic rearrangement reaction has been developed. The intermolecular rearrangement occurs between in situ generated donor-acceptor gold-carbenes and cinnamyl alcohols via tandem oxonium ylide formation. The desired rearranged product has been accomplished selectively over more conventional O-H insertion, cyclopropanation, cycloaddition, and C-H functionalization products under mild, open-air conditions. The scope of the work has been illustrated by synthesizing a new class of substrates that can be used for constructing complex molecular targets.

Boron‐Catalyzed C−C Functionalization of Allyl Alcohols

“…It was only recently that activation of diazo compounds by boron was reported. In continuation of our earlier work, [29] we report b-(sp 2 )-carbon functionalization of cinnamyl alcohol with diazo derived donor-acceptor carbenes (Scheme 1). [27] More recently, a seminal work by Zhang on B(C 6 F 5 ) 3 catalyzed ortho-substitution of phenols is noteworthy.…”

“…[28] Nonetheless, the full potential of B(C 6 F 5 ) 3 with the diazo reagents still needs to be realized. In continuation of our earlier work, [29] we report b-(sp 2 )-carbon functionalization of cinnamyl alcohol with diazo derived donor-acceptor carbenes (Scheme 1). [30] To the best our knowledge, the present work is the first report in this direction.…”

Melding of Experiment and Theory Illuminates Mechanisms of Metal-Catalyzed Rearrangements: Computational Approaches and Caveats

“…Efforts to achieve these couplings stereoselectively with transition-metal catalysts have enabled the development of reliable and effective methods to introduce new stereogenic centers in complex target molecules. 2,3 The most commonly used transition-metal catalysts for these reactions are rhodium-and copper-based catalysts, 4,5 but catalysts based on other metals, such as gold, 6,7 ruthenium, [8][9][10][11] cobalt, 12,13 palladium, [14][15][16] silver, 17 nickel, 18 and iron, [19][20][21][22][23][24][25][26] also have been developed for these purposes. In 1981, Doyle and co-workers 27 brought new life to the field of transition-metal-catalyzed [2,3]-sigmatropic rearrangements, building on past work by Kirmse and Kapps, 28 by demonstrating utility for organic synthesis (Scheme 1).…”

Rhodium-Catalyzed Carbene Transfer Reactions for Sigmatropic Rearrangement Reactions of Selenium Ylides

“…In the presence of an electrophilic carbene, the lighter group VI elements, oxygen and sulfur, react under ylide formation and subsequent rearrangement. − The heavier homologues have been investigated much less, and selenium ylides find very limited applications. , Even today, there are only singular examples that describe sigmatropic rearrangement reactions of selenium ylides via deprotonation reactions of a C–H acidic, preformed selenonium salt under basic reaction conditions . In 1995, Uemura reported a single example describing the catalytic rearrangement of a selenium ylide using copper or rhodium catalysts, though the efficiency and yield were poor …”