Reactions on a Solid Surface. A Simple, Economical, and Efficient Acylation of Alcohols and Amines over Al<sub>2</sub>O<sub>3</sub>
作者:Veejendra K. Yadav、K. Ganesh Babu
DOI:10.1021/jo035412f
日期:2004.1.1
Al2O3 brings about a rapid acylation of a range of alcohols and amines with acid chlorides and acid anhydrides, respectively. Amines are easily Boc- and Cbz-protected on reaction with Boc-anhydride and Cbz-Cl, respectively. The acylation of phenols is slow enough to allow chemoselective acylation of alcohols and amines in the presence of phenols.
Al 2 O 3分别使多种醇和胺分别与酰氯和酸酐快速酰化。分别与Boc酸酐和Cbz-Cl反应时,胺很容易受到Boc和Cbz保护。酚的酰化足够慢,以允许在酚存在下醇和胺的化学选择性酰化。
Cobalt-catalyzed carboxylation of propargyl acetates with carbon dioxide
The cobalt-catalyzed carboxylation of propargyl acetates with CO2 (1 atm) is described. The reaction proceeds at room temperature in the presence of Mn powder as a reducing reagent. Various propargyl acetates are converted to the corresponding carboxylic acids in good to high yields.
Trimethylsilylenolethers were prepared by using a combination of chlorotrimethylsilane and 1,8-diazabicyclo[5.4.0]undec-7-ene in good yields. Trimethylsilylation of acetylenes was also achieved with the same reagents in the presence of silver salt as catalyst.
Synthesis of Polysubstituted Iodobenzene Derivatives from Alkynylsilanes and 1,3-Dienes via Diels–Alder/Oxidation/Iodination Reaction Sequence
作者:Robert Möckel、Gerhard Hilt
DOI:10.1021/acs.orglett.5b00306
日期:2015.4.3
The cobalt-catalyzed Diels–Alder reaction of trimethylsilyl-substituted alkynes with 1,3-dienes led to dihydroaromatic intermediates which were transformed into iodobenzene derivatives. For this transformation, the dihydroaromatic intermediates had to be oxidized and the trimethylsilyl-substituted arene had to undergo a silicon–iodine exchange reaction. For this purpose, a number of oxidizing agents
A highly efficient organo-catalytic protocol for the trimethylsilylation of terminal alkynes and N-silylation of indoles employing Ruppert's reagent as a trimethylsilyl source have been developed under solvent and fluoride free conditions.