stereoselectivities. The intermediary alkenylmanganese compounds were trapped by various electrophiles. The reaction was clearly oxygen-assisted since 6-dodecyne was completely recovered unchanged. Diallylation products were obtained in the presence of air. Allylmagnesation and diallylation of these acetyleniccompoundscatalyzed by manganesesalts are also disclosed.
Hwu, Jih Ru; Hakimelahi, Gholam Hosein; Wong, Fung Fuh, Angewandte Chemie, 1993, vol. 105, # 4, p. 591 - 592
作者:Hwu, Jih Ru、Hakimelahi, Gholam Hosein、Wong, Fung Fuh、Lin, Chun Chieh
DOI:——
日期:——
Highly enantioselective addition of linear alkyl alkynes to linear aldehydes
作者:Yuhao Du、Mark Turlington、Xiang Zhou、Lin Pu
DOI:10.1016/j.tetlet.2010.07.082
日期:2010.9
It is discovered that the use of biscyclohexylamine (Cy(2)NH) as an additive can greatly enhance the enantioselectivity for the reaction of linear alkyl alkynes with linear aldehydes. The combination of (S)-BINOL (20 mol %), Cy(2)NH (5 mol %), ZnEt(2) (2 equiv), and Ti(O(i)Pr)(4) (0.5 equiv) catalyzes the reaction at room temperature in diethyl ether solution with 81-89% ee and 57-77% yield. (C) 2010 Elsevier Ltd. All rights reserved.
Catalytic Access to Functionalized Allylic
<i>gem</i>
‐Difluorides via Fluorinative Meyer–Schuster‐Like Rearrangement
functionalized allylic gem‐difluorides via catalytic fluorinative Meyer–Schuster‐like rearrangement is disclosed. This transformation proceeded with readily accessible propargylicfluorides, and low‐cost B–F reagents and electrophilic reagents by sulfide catalysis. A series of iodinated, brominated, and trifluoromethylthiolated allylic gem‐difluorides that were difficult to access by other methods were
Total Synthesis of the Alkoxydioxines (+)- and (−)-Chondrillin and (+)- and (−)-Plakorin via Singlet Oxygenation/Radical Rearrangement
作者:Patrick H. Dussault、C. Todd Eary、Kevin R. Woller
DOI:10.1021/jo981128q
日期:1999.3.1
unaffected by the presence of polar co-solvents or by the incorporation of a group able to selectively hydrogen bond to the product hydroperoxide. Photoisomerization of the (E)-4-hydroperoxy-2-enone rearrangement products results in irreversible ring closure to furnish diastereomeric mixtures of enantiomericallyenriched dioxinols. The strategy is applied to the total synthesis of the alkoxydioxine natural