|
| ||
|
|
||
Carbonyl Functionality (carbonyl + functionality)
Selected AbstractsAn Exceptionally Simple and Catalytic Method for Regeneration of Carbonyl Functionality from the Corresponding 1,3-Oxathiolanes.CHEMINFORM, Issue 35 2002Ejabul Mondal Abstract For Abstract see ChemInform Abstract in Full Text. [source] The First General and Selective Palladium(II)-Catalyzed Alkoxycarbonylation of Arylboronates: Interplay among Benzoquinone-Ligated Palladium(0) Complex, Organoboron, and Alcohol SolventADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 2-3 2010Yoshihiko Yamamoto Abstract Methoxycarbonylation of aryl- and alkenylboron compounds was performed using the palladium(II) acetate/triphenylphosphine [Pd(OAc)2/PPh3] catalyst with p -benzoquinone as a stoichiometric oxidant in methanol at ambient temperature to obtain the corresponding methyl esters in good yields. A wide variety of functional groups including various carbonyl functionalities, nitrile, nitro, sulfone, and unprotected pyrrole rings were tolerated in the methoxycarbonlation, while the use of higher alcohols except for tert -butanol afforded various p -chlorobenzoates in moderate to high yields. The catalytic alkoxycarbonylation proceeded without any acid or base additive, and an oxidative transmetalation step is proposed to explain the exceptional efficacy of this protocol. DFT and MP2 calculations support the proposed mechanism. [source] 1-Alkoxyamino-2-nitroalkanes as Key Building Blocks for a Chemo- and Diastereoselective Synthesis of a New Type of Polyfunctionalized N -AlkoxypiperidineEUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 28 2010M. Ángeles López-García Abstract A highly efficient conversion of ,-nitrostyrenes into a new kind of functionalized N -alkoxy-2-hydroxypiperidine in two steps was developed, giving excellent yields and diastereoselectivity. The prepared compounds are the first examples of N -alkoxy-2-hydroxypiperidines. The synthetic approach involved the conjugate addition of alkoxyamines to ,-nitrostyrenes, followed by Michael addition of the isolated nitroalkoxyamines to ,,,-unsaturated carbonyl compounds, and intramolecular addition of the alkoxyamino group to the carbonyl functionality of the (non-isolated) adducts. Although three stereogenic centers are formed, only one diastereoisomer was detected. This unprecedented sequence of reactions can also be performed in a one-pot fashion. [source] Synthesis of Trisubstituted Pyrroles from Rhodium-Catalyzed Alkyne Head-to-Tail Dimerization and Subsequent Gold- Catalyzed CyclizationADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 9 2009Hong Mei Peng Abstract Dimerization of N -protected propargylic amines in a rather rare head-to-tail mode has been achieved under mild conditions with high selectivity using rhodium catalysts. The N -protecting group could be a sulfonyl, carbamate, or carbonyl functionality and (cyclooctadiene)rhodium chloride dimer/1,1,-bis(diphenylphosphino)ferrocene {[Rh(COD)Cl]2/dppf} as well as tris(triphenylphosphine)rhodium chloride [Rh(PPh3)3Cl] proved to be active catalysts. In addition, these functionalized gem -enynes subsequently undergo selective gold(III)-catalyzed intramolecular hydroamination to give trisubstituted pyrroles under mild conditions. [source] | ||||||||||