Lactone Radical Cyclizations and Cyclization Cascades Mediated by SmI<sub>2</sub>–H<sub>2</sub>O
作者:Dixit Parmar、Hiroshi Matsubara、Kieran Price、Malcolm Spain、David J. Procter
DOI:10.1021/ja3047975
日期:2012.8.1
Unsaturated lactones undergo reductive radicalcyclizations upon treatment with SmI(2)-H(2)O to give decorated cycloheptanes in a single highly selective operation during which up to three contiguous stereocenters are generated. Furthermore, cascade processes involving lactones bearing two alkenes, an alkene and an alkyne, or an allene and an alkene allow "one-pot" access to biologically significant
An efficient synthesis of carbazoles from PtCl2-catalyzed cyclization of 1-(indol-2-yl)-2,3-allenols
作者:Wangqing Kong、Chunling Fu、Shengming Ma
DOI:10.1039/b909649c
日期:——
The PtCl2-catalyzed reaction of 1-(indol-2-yl)-2,3-allenols occurred smoothly to form carbazoles by connecting the 3-carbon atom of indole with the 4-carbon atom of the allenol moiety, referring to the carbon atom connected to the hydroxyl group.
Studies on Electrophilic Interaction of 2,3-Allenols with Electrophilic Halogen Reagents: Selective Synthesis of 2,5-Dihydrofurans, 3-Halo-3-alkenals, or 2-Halo-2-alkenyl Ketones
作者:Jing Li、Chunling Fu、Guofei Chen、Guobi Chai、Shengming Ma
DOI:10.1002/adsc.200800088
日期:2008.6.9
iodine (I2) afforded 2,5-dihydrofurans while that of readily available 1-aryl or 1-methyl substituted 2,3-allenols with bromine (Br2), N-bromosuccinimide (NBS), I2 or N-iodosuccinimide (NIS) formed the not easily available but synthetically useful 3-halo-3-alkenals and 2-halo-2-alkenyl ketones with good selectivity and yields via a sequential electrophilic interaction of X+ with the allene moiety, 1,2-aryl
PdI2-Catalyzed Coupling–Cyclization Reactions Involving Two Different 2,3-Allenols: An Efficient Synthesis of 4-(1′,3′-Dien-2′-yl)-2,5-dihydrofuran Derivatives
作者:Youqian Deng、Jing Li、Shengming Ma
DOI:10.1002/chem.200800167
日期:2008.5.9
Transition-metal-catalyzed dimeric coupling-cyclizationreactions of twodifferent2,3-allenols afforded 4-(1',3'-dien-2'-yl)-2,5-dihydrofuranderivatives3. 2-Substituted 2,3-allenols1 cyclized to form the 2,5-dihydrofuran ring, whereas the 2-unsubstituted 2,3-allenols 2 provided the 1,3-diene unit at the 4-position. The reaction is proposed to proceed through an oxypalladation, insertion, and beta-hydroxide
Olefin-Directed Palladium-Catalyzed Regio- and Stereoselective Hydroboration of Allenes
作者:Can Zhu、Bin Yang、Youai Qiu、Jan-E. Bäckvall
DOI:10.1002/chem.201505130
日期:2016.2.24
An olefin‐directed palladium‐catalyzed regio‐ and stereoselective hydroboration of allenes has been developed to afford fully substituted alkenylboron compounds. The reaction showed a broad substrate scope: a number of functionalized allenes, including 2,3‐dienoate, 3,4‐dienoate, 3,4‐dienol, 1,2‐allenylphosphonate, and alkyl‐substituted allenes, could be used in this olefin‐directed allene hydroboration