72003-93-1Relevant articles and documents
Synthetic Studies of the Rubellin Natural Products: Development of a Stereoselective Strategy and Total Synthesis of (+)-Rubellin C
Gartman, Jackson A.,Tambar, Uttam K.
, p. 11237 - 11262 (2021/08/16)
This manuscript describes our studies of the class of natural products known as the rubellins, culminating in the total synthesis of (+)-rubellin C. These anthraquinone-based natural products contain a variety of stereochemical and architectural motifs, including a 6-5-6-fused ring system, 5 stereogenic centers, and a central quaternary center. Herein, we report our development of a strategy to target the stereochemically dense core and anthraquinone nucleus, including approaches such as a bifunctional allylboron and vinyl triflate reagent, an anthraquinone benzylic metalation strategy, and a late-stage anthraquinone introduction strategy. Our studies culminate in a successful route to highly functionalized anthraquinone-based natural product scaffolds and a stereoselective total synthesis of (+)-rubellin C. These strategies and outcomes will aid in synthetic planning toward anthraquinone-based natural products of high interest.
Total synthesis of sparstolonin B via a palladium-catalyzed aldehyde α-arylation
Kim, Dalton,Nash, Aaron,De Brabander, Jef,Tambar, Uttam K.
, p. 3787 - 3790 (2018/05/24)
A concise and convergent total synthesis of sparstolonin B was developed. A palladium-catalyzed aldehyde α-arylation was utilized to construct the carbon skeleton of the natural product. A subsequent simple one-pot procedure effected global deprotection and closure of the final two rings via an unusual autoredox mechanism for the conversion of a bis-hydroquinone intermediate to the natural product. The 6 step synthetic sequence was realized in 18% overall yield.
Beyond directed ortho metalation: Ru-catalyzed CAr-O activation/cross-coupling reaction by amide chelation
Zhao, Yigang,Snieckus, Victor
, p. 11224 - 11227 (2014/09/29)
Disclosed is a new, catalytic, and general methodology for the chemical synthesis of biaryl, heterobiaryl, and polyaryl molecules by the cross-coupling of o-methoxybenzamides with aryl boroneopentylates. The reaction is based on the activation of the unreactive C-OMe bond by the proximate amide directing group using catalytic RuH2(CO)(PPh3)3 conditions. A one-step, base-free coupling process is thereby established that has the potential to supersede the useful two-step directed ortho metalation/cross- coupling reaction involving cryogenic temperature and strong base conditions. High regioselectivity, orthogonality with the Suzuki-Miyaura reaction, operational simplicity, minimum waste, and convenient scale-up make these reactions suitable for industrial applications.
