Development of a Method for the Reductive Cyclization of Enones by a Titanium Catalyst
作者:Natasha M. Kablaoui、Stephen L. Buchwald
DOI:10.1021/ja954192n
日期:1996.1.1
which bis(trimethylphosphine)titanocene is used to catalyze the reductive cyclization of enones to cyclopentanols via a metallacyclic intermediate has been developed. The key step in the process is the cleavage of the titanium−oxygen bond in the metallacycle by a silane to regenerate the catalyst. Mechanistic aspects of the reaction are discussed and the diastereoselectivity of the transformation is studied
Effect of InCl 3 on the addition of Grignard reagents to α,β-unsaturated carbonyl compounds
作者:Brian G. Kelly、Declan G. Gilheany
DOI:10.1016/s0040-4039(01)02263-8
日期:2002.1
Control of 1,2- versus 1,4-addition of organometallic reagents to enones remains a long-standing problem. There is still no satisfactory 1,2-directing agent comparable to the 1,4-directing effect of copper salts. We report that the presence of just 5 mol% indium(III) chloride can significantly alter the amount of 1,2-product formed in these reactions.
Neighboring group participation in Lewis acid-promoted [3 + 4] and [3 + 5] annulations. The synthesis of oxabicyclo[3.n.1]alkan-3-ones
作者:Gary A. Molander、Kimberly O. Cameron
DOI:10.1021/ja00056a002
日期:1993.2
2-(alkoxycarbon)-m-oxabicyclo[3.n.1]alkan-3-ones can be constructed by this process in which two new carbon-carbon bonds are generated. Unusually high regioncontrol is observed, and good to excellent stereochemicalcontrol can be achieved at virtually every position on the new carbocycles. Intramolecular neighboringgroupparticipation is proposed to explain the unusually high selectivities attained in the annulation
Efficient Addition of Allylsilanes to α,β-Enones Using Catalytic Indium and Trimethylsilyl Chloride
作者:Phil Ho Lee、Dong Seomoon、Sundae Kim、K. Nagaiah、S. V. Damle、Kooyeon Lee
DOI:10.1055/s-2003-41017
日期:——
β-Enones undergo an efficient Hosomi-Sakurai reaction with allyltrimethylsilane, in which a catalytic amount of indium is used in the presence of trimethylsilylchloride as an activator under mild conditions to produce the conjugateaddition products in good yields.
作者:Justin A. Hilf、Michael S. Holzwarth、Scott D. Rychnovsky
DOI:10.1021/acs.joc.6b01370
日期:2016.11.4
Pyridine rings are common structural motifs found in a number of biologically active compounds, including some top-selling pharmaceuticals. We have developed a new approach to access substituted pyridines. The method aims to provide a reliable synthesis of a diverse range of substituted pyridines through a three-step procedure. Readily available enones are first converted into 1,5-dicarbonyls through