Decarboxylative Acylation of Cyclic Enamides with α-Oxocarboxylic Acids by Palladium-Catalyzed C–H Activation at Room Temperature
作者:Hua Wang、Li-Na Guo、Xin-Hua Duan
DOI:10.1021/ol301801r
日期:2012.9.7
efficient catalytic decarboxylative acylation of unactivated sp2 (alkenyl) C–H bonds has been developed. Various substituted α-oxocarboxylic acids with different electronic properties react under mild conditions to afford a diverse range of β-acyl enamide products in good yields. The reaction is proposed to proceed via a cyclic vinylpalladium intermediate, facilitating the decarboxylative dehydrogenative
Cracked under strain: Strained allylic cyclobutanols and cyclopropanols readily undergo a ring expansion described by the title rearrangement. This reaction is promoted by catalytic amounts of 1 and displays high tolerance with respect to the substrate scope. The corresponding β‐fluoro spiroketone products are isolated in high yields and with excellent stereoselectivities. EDG=electron‐donating group
The present manuscript describes a high-yielding enantioselective semipinacol transposition, initiated by an electrophilic iodination event. The title transformation makes use of the anionic phase-transfer catalysis (PTC) paradigm for chirality induction. Thus, when combined appropriately, the insoluble cationic iodinating reagent S9 and the lipophilic phosphoric acid L9 act as an efficient source
The present invention provides compounds of formula (I) and pharmaceutically acceptable salts thereof, wherein n, X1, X2, R1, R2, R3, R4, R5, R6, R7, R8, R9, R10, R11, R12and R13 are as defined in the specification, processes for their preparation, pharmaceutical compositions containing them and their use in therapy.
A simple route for the synthesis of 4-chlorochromenes and chroman-4-ones
作者:G. Ariamala、K.K. Balasubramanian
DOI:10.1016/0040-4039(88)85197-9
日期:1988.1
A one pot synthesis of a number of 4-chlorochromenes and chroman-4-ones was achieved from γ-chloropropargyl aryl ethers proceeding through Claisen rearrangement, depending upon the solvent of choice.