Palladium(II)-Catalyzed SN2‘ Reactions of α-Allenic Acetates. Stereoconvergent Synthesis of (Z,E)-2-Bromo-1,3-dienes
摘要:
The reaction of acetylated a-allenic alcohols with LiBr in the presence of 1.5 mol % of Pd(OAc)(2) provides easy access to substituted (Z,E)-2-bromo-1,3-dienes in good yields with excellent diastereoselectivity. Both secondary and tertiary acetates as well as terminal and nonterminal allenes were studied to investigate the scope and the limitations of the reaction. A mechanism is proposed to clarify how a diastereomeric mixture of the starting compound is transformed into a single diastereomer of the product.
Rapid synthesis of bis(hetero)aryls by one-pot Masuda borylation–Suzuki coupling sequence and its application to concise total syntheses of meridianins A and G
作者:Eugen Merkul、Elisabeth Schäfer、Thomas J. J. Müller
DOI:10.1039/c1ob05310h
日期:——
3-(Hetero)aryl substituted indoles, 7-azaindoles, and pyrroles can be obtained in a very concise fashion via a one-pot Masuda borylation–Suzuki coupling sequence. The concise total syntheses of the marine natural products meridianins A (5) and G (4i) nicely illustrate the utility of this methodology.
A novel one-pot three-component synthesis of 3-halofurans and sequential Suzuki coupling
作者:Alexei S. Karpov、Eugen Merkul、Thomas Oeser、Thomas J. J. Müller
DOI:10.1039/b502324f
日期:——
electrophilic addition to an ynone, with concomitant deprotection and cyclocondensation, opens a new one-potsynthesis of 3-halofurans; the method can be readily elaborated to a new sequential Sonogashira-addition-cyclocondensation-Suzuki reaction to furnish 2,3,5-trisubstituted furans in a one-pot fashion.
Photocatalyst size controls electron and energy transfer: selectable E/Z isomer synthesis via C–F alkenylation
作者:A. Singh、C. J. Fennell、J. D. Weaver
DOI:10.1039/c6sc02422j
日期:——
Photocatalytic alkene synthesis can involve electron and energy transfer processes. The structure of the photocatalyst can be used to control the rate of the energy transfer, providing a mechanistic handle...
Consecutive One-Pot Sonogashira-Glaser Coupling Sequence - Direct Preparation of Symmetrical Diynes by Sequential Pd/Cu Catalysis
作者:Eugen Merkul、Dominik Urselmann、Thomas J. J. Müller
DOI:10.1002/ejoc.201001472
日期:2011.1
Sonogashira coupling and the catalytic Glaser coupling are both catalyzed by the Pd-Cu complex couple and can be concatenated to a consecutivesequentiallyPd/Cu-catalyzed process in a one-pot fashion, and air oxygen serves as the only oxidant in the second step. In a pseudo-four-component synthesis, a broad variety of symmetrically substituted 1,4-bis(hetero)aryl-1,3-butadiynes are obtained in good