证明了迄今为止未知的LDA诱导的苄基1-炔基砜向1 H -2-苯并噻喃-S,S-二氧化物的转化。苄基碳负离子可通过两种方式进入,被认为是由于芳香族的暂时破坏而环化的。通过ReactIR分析观察到了关键中间体。噻吩衍生物也适合环化,形成7 H-噻吩并[2,3- c ] thiopyran- S,S-二氧化物。
Practical regio- and stereoselective azidation and amination of terminal alkenes
作者:Olatunji S. Ojo、Octavio Miranda、Kyle C. Baumgardner、Alejandro Bugarin
DOI:10.1039/c8ob02734j
日期:——
There is significant interest in developing more rapid and efficient production of nitrogen-containing allylic compounds, as widely used in various syntheses. This work reports a variety of allylic azides and allylic amines synthesized by an efficient, new one-pot protocol that employs readily available terminal alkenes as starting materials. This method is highly regio- and stereoselective, affording
The present invention is directed to a reagent for use in the preparation of organomagnesium compounds as well as to a method of preparing such organomagnesium compounds. The present invention furthermore provides a method of preparing functionalized or unfunctionalized organic compounds as well as the use of the reagents of the present invention in the preparation of organometallic compounds and their reaction with electrophiles. Finally, the present invention is directed to the use of lithium salts - LiY in the preparation of organometallic compounds and their reactions with electrophiles and to an organometallic compound which is obtainable by the disclosed method.
Cobalt-Catalyzed Directed Alkylation of Olefinic C–H Bond with Primary and Secondary Alkyl Chlorides
作者:Naohiko Yoshikai、Takeshi Yamakawa、Yuan Seto
DOI:10.1055/s-0034-1379247
日期:——
A cobalt–N-heterocyclic carbene catalytic system promotes pyridine-directed olefinic C–H alkylation reactions using a variety of primary and secondary alkyl chlorides under mild conditions. Radical clock experiments suggest that the reaction involves single-electron transfer from the cobalt intermediate to the alkyl chloride.
Palladium-Catalyzed Oxidative Rearrangement of Diaryl Alkenyl Carbinols to β,β-Diaryl α,β-Unsaturated Ketones
作者:David Rosa、Arturo Orellana
DOI:10.1021/ol201177t
日期:2011.7.15
An unusual oxidative palladium-catalyzed rearrangement of diaryl alkenyl carbinols to β,β-diaryl α,β-unsaturated ketones is described. The geometry of the alkene product is not determined by the electronic nature of the aryl substitutents but rather is determined by substitution pattern on the aryl rings. The reaction proceeds in good yields, utilizes oxygen at atmospheric pressure as the terminal
SimplePhos ligands proved to be very powerful ligands in the generation of quaternary stereogeniccenters by Michael addition of alkenyl-aluminum reagents to cyclic enones. Using commercially available and easily accessible alkenylbromides as alane precursors the present procedure offers a facile access to β-alkenyl-substituted cyclohexanones with high enantioselectivities up to 96%.