Organometallic-type reactions in aqueous media mediated by indium. Allylation of acyloyl-imidazoles and pyrazoles. Regioselective synthesis of β,γ-unsaturated ketones
作者:Vernal J. Bryan、Tak-Hang Chan
DOI:10.1016/s0040-4039(97)01512-8
日期:1997.9
Indiummediated coupling of allylic bromide with acyloyl-imidazoles or pyrazoles in aqueousmedia gives the corresponding tertiary alcohols or ketones in good yield. The reaction provides a facile regioselective synthesis of β,γ-unsaturated ketones and its usefulness is demonstrated by the synthesis of the monoterpene artemesia ketone.
?-Cleavage of Bis(homoallylic) Potassium Alkoxides. Two-Step Preparation of Propenyl Ketones from Carboxylic Esters. Synthesis ofar-Turmerone, ?-Damascone, ?-Damascone, and ?-Damascenone
作者:Roger L. Snowden、Simon M. Linder、Bernard L. Muller、Karl H. Schulte-Elte
DOI:10.1002/hlca.19870700721
日期:1987.11.4
The transformation of 36 bis(homoallylic) alcohols VII to alkenones IX and Xvia β-cleavage of their potassiumalkoxides VIIa in HMPA has been investigated (cf. Scheme 2). These studies have established an order of β-cleavage for 2-propenyl, 1-methyl-2propenyl, 2-methyl-2-propenyl, 1,1-dimethyl-2propenyl, and benzyl groups in alkoxides 49a–56a and have allowed a comparison between the β-cleavege reaction
Fragmentation of homoallylic alkoxides. Synthesis of propenyl and 2-methylpropenyl ketones from carboxylic esters
作者:Roger L. Snowden、Bernard L. Muller、Karl H. Schulte-Elte
DOI:10.1016/s0040-4039(00)86824-0
日期:1982.1
An efficient two-step synthesis of propenyl and 2-methylpropenyl ketonesfromcarboxylic esters is described which uses as the key step the fragmentation of a potassium dihomoallylic alkoxide under mild thermolytic conditions.
Enantioselective synthesis of cyclic allylboronates by Mo-catalyzed asymmetric ring-closing metathesis (ARCM). A one-pot protocol for net catalytic enantioselective cross metathesis
作者:Jesper A. Jernelius、Richard R. Schrock、Amir H. Hoveyda
DOI:10.1016/j.tet.2004.06.017
日期:2004.8
Mo-catalyzed asymmetric ring-closing metathesis (ARCM) reactions are used to synthesize cyclic allylboronates of high optical purity (89% ee to >98% ee). A one-pot procedure involving formation of allylboronates, Mo-catalyzed ARCM and functionalization of the optically enriched cyclic allylboronates constitutes net asymmetric crossmetathesis (ACM). Structural modification of ARCM products include
Indium(III) Chloride-Catalyzed Coupling Reaction of Acid Chlorides and Allylic Tins
作者:Katsuyuki Inoue、Yasuhisa Shimizu、Ikuya Shibata、Akio Baba
DOI:10.1055/s-2001-17482
日期:——
Allylic tributyltins and acid chlorides are effectively coupled to yield allylic ketones in indium(III) chloride-catalyzed reactions. In the case of γ-unsubstituted allylic tins, the assistance of a phosphine is essential to prevent further allylation of the produced ketones.