A New Strategy for Deprotonative Functionalization of Aromatics: Transformations with Excellent Chemoselectivity and Unique Regioselectivities Using t-Bu-P4 Base
摘要:
A new strategy for deprotonative functionalization of aromatics using t-Bu-P4 base has been developed, and highly chemoselective transformations have been achieved with unique regioselectivities.
Barbier type reaction with lithium metal has been tested under sonication on pyridines, a cinnoline and on various diazines. This very convenient method allows a very fast and smooth functionalization of these heterocycles.
Synthesis of 1,3-dihydrofuro[3,4-]pyridines and 5,7-dihydrofuro[3,4-]pyridines by intramolecular Diels-Alder reactions of pyrimidines. Investigation of the effect of steric interactions on the reaction rate
作者:A.E. Frissen、A.T.M. Marcelis、D.G. Buurman、C.A.M. Pollmann、H.C. van der Plas
DOI:10.1016/s0040-4020(01)89505-3
日期:1989.1
5-propynyloxymethylpyrimidines were synthesized and their intramolecularDiels-Alderreaction was studied. The products of the reaction were 5,7-dihydrofuro[3,4-]pyridines and 1,3-dihydrofuro[3,4-]pyridines, respectively. Introduction of one or two alkyl (aryl) groups at the α or γ position of the side-chain of the 5-propynyloxymethylpyrimidines results in an increased reaction rate. This phenomenon is discussed in terms
5-(Pyrimidinyl)magnesium and cerium chlorides were prepared via the halogen-metal exchange of 5-bromopyrimidine with ethylmagnesium chloride and a sequential treatment of butyllithium and cerium(III) chloride, respectively. In a similar way, 5-[2,4-di(tert-butoxy)pyrimidinyl]magnesium and cerium chlorides were prepared from the reaction of 5-bromo-2,4-di(tert-butoxy)-pyrimidine with ethylmagnesium chloride and butylcerium chloride, respectively.
Preparation of a series of new aryl diazinyl ketoximes (7a,b - 12a,b) required as synthetic building blocks is described. Separation of the E/Z-isomers obtained was achieved by means of chromatography, their configuration was assigned using nmr techniques. Moreover, procedures for the synthesis of the starting ketones (1b - 6b) are given.
FRISSEN, A. E.;MARCELIS, A. T. M.;BUURMAN, D. G.;POLLMANN, C. A. M.;VAN, +, TETRAHEDRON, 45,(1989) N7, C. 5611-5620
作者:FRISSEN, A. E.、MARCELIS, A. T. M.、BUURMAN, D. G.、POLLMANN, C. A. M.、VAN, +