Silver(I)-Catalyzed Aminocyclization of 2,3-Butadienyl and 3,4-Pentadienyl Carbamates: An Efficient and Stereoselective Synthesis of 4-Vinyl-2-oxazolidinones and 4-Vinyltetrahydro-2<i>H</i>-1,3-oxazin-2-ones
作者:Masanari Kimura、Shuji Tanaka、Yoshinao Tamaru
DOI:10.1246/bcsj.68.1689
日期:1995.6
Silver(I) salts in combination with an appropriate base (mostly triethylamine) catalyzed the aminocyclization of N-substituted 2,3-butadienyl carbamates 1 (benzene, 50 °C) to provide 4-vinyl-2-oxazolidinones 2 in good yields. The stereoselectivity (trans-2/cis-2) ranged from 1.4 for C5-Me to >30 for C5-phenyl, isopropenyl, and t-butyl derivatives. 3,4-Pentadienyl tosylcarbamates 3, the one-carbon higher homologues of 1, underwent a similar cyclization to give 4-vinyltetrahydro-2H-1,3-oxazin-2-one 4 in synthetically useful yields and in higher trans selectivities than 1.
Solvent Assisted Addition of Tetraallylic, Tetraallenic and Tetrapropargylic Stannanes to Aldehydes and Acetals
作者:Adam McCluskey、I Wayan Muderawan、Muntari Young、David J. Young
DOI:10.1055/s-1998-1807
日期:1998.8
Tetraallylic, tetraallenic and tetrapropargylic stannanes (0.25 eq) react with aldehydes in methanol to provide unsaturated alcohols. These reactions proceed in methanol to provide unsaturated alcohols. These reactions proceed exclusively with allylic rearrangement for tetra(2-butenyl)tin 2b and tetra(1,2-butadienyl)tin 5e and predominantly with allylic rearrangement for tetrapropadienyltin 5c and tetra(2-butynyl)tin 6e. The corresponding TFA catalysed reactions of dimethyl acetals with 5c and 6e are highly regioselective with allylic rearrangement.
HIGHLY REGIOSELECTIVE AND STEREOSELECTIVE RADICAL ADDITION OF<i>p</i>-TsBr TO α-ALLENIC ALCOHOLS AND THEIR ELIMINATION REACTION: SYNTHESIS OF β-<i>p</i>-TOSYL-SUBSTITUTED α,β-UNSATURATED KETONES
作者:Suk-Ku Kang、Byung-Su Ko、Dong-Min Lee
DOI:10.1081/scc-120014030
日期:2002.1
ABSTRACT Regio- and stereoselective radical addition of α-allenicalcohols with p-TsBr in the presence of a catalytic amount of AIBN afforded (E)-γ-bromo-β-sulfonyl allylic alcohols in moderate yields. The base-promoted 1,4-elimination followed by isomerization to give β-sulfonyl-α,β-unsaturated ketones is described.
Studies on the radical addition reaction of perfluoroalkyl iodides with 2,3-allenols and the Pd-catalyzed kinetic resolution via Sonogashira coupling reaction
作者:Zhichao Ma、Rong Zeng、Chunling Fu、Shengming Ma
DOI:10.1016/j.tet.2011.08.044
日期:2011.11
A radical addition reaction promoted by Na2S2O4 of perfluoroalkyliodides with 2,3-allenols affording E/Z mixtures of 3-iodo-4-perfluoroalkyl-substituted allylic alcohols has been studied. Kinetic resolution with Sonogashira coupling reaction was applied to afford the Z isomer of 3-iodo-4-perfluoroalkyl-substituted allylic alcohol (Z-3) and the E isomer of conjugated enynic diols (E-5) in 39–52% and
已经研究了由全氟烷基碘化物的Na 2 S 2 O 4与2,3-烯醇促进的自由基加成反应,得到3碘-4-全氟烷基取代的烯丙基醇的E / Z混合物。与Sonogashira偶联反应动力学拆分施加到得到Ž 3-碘-4-全氟烷基-取代的烯丙醇的异构体(ž - 3)和Ë缀合enynic二醇(异构体ë - 5)在39-52%和22分别为–40%的收益率。
Palladium-catalyzed arylation of α-allenic alcohols with hypervalent iodonium salts: Synthesis of epoxides and diol cyclic carbonates
作者:Suk-Ku Kang、Tokutaro Yamaguchi、Sung-Jae Pyun、Yong-Tack Lee、Tae-Gon Baik
DOI:10.1016/s0040-4039(98)00076-8
日期:1998.4
Pd(0)-catalyzed arylation of the aryl-substituted α-allenic alcohols with hypervalent iodonium salts afforded substituted trans-epoxides. Alternatively, arylation of the alkyl-substituted α-allenic alcohols in the presence of K2CO3 afforded syn-diol cyclic carbonates and trans-epoxides in the presence of Cs2CO3.
Pd(0)催化的芳基取代的α-烯醇与高价碘鎓盐的芳基化反应提供了取代的反式环氧化物。或者,在K 2 CO 3的存在下烷基取代的α-烯丙醇的芳基化在Cs 2 CO 3的存在下提供了顺式二醇环状碳酸酯和反式环氧化物。