An Efficient Approach for Monofluorination via Highly Regioselective Fluorohydroxylation Reaction of 3-Aryl-1,2-allenes with Selectfluor
摘要:
The internal C-C double bond in 3-aryl-1,2-allenes was highly regioselectively fluorohydroxylated to afford 2-fluoroalken-3-ols in 37-88% yields by using Selectfluor as the electrophilic reagent. The regioselectivity may be determined by the electronic effect, while the reactivity may be controlled by the stabilization effect of the aryl group in the allylic cationic intermediates.
Synthesis of Arylallenes by Palladium-Catalyzed Retro-Propargylation of Homopropargyl Alcohols
摘要:
Treatment of tertiary homopropargyl alcohol with aryl halide under palladium catalysis provided arylallenes regioselectively. The reaction includes retropropargylation, which proceeds in a concerted fashion via a cyclic transition state and transfers the stereochemistry of homopropargyl alcohols through C-C bond cleavage. The present method enables the use of homopropargyl alcohols as allenylmetal equivalents.
Highly Selective Mild Stepwise Allylation of <i>N</i>-Methoxybenzamides with Allenes
作者:Rong Zeng、Chunling Fu、Shengming Ma
DOI:10.1021/ja303790s
日期:2012.6.13
allylation of N-methoxybenzamides 1 with polysubstituted allenes is reported. This C-H functionalization involving allenes is conducted under very mild conditions (-20 °C or room temperature) and compatible with ambient air and moisture, and it can be applied to terminal or internal allenes with different synthetically attractive functional groups. Highly efficient axial chirality transfer has been realized
报道了 N-甲氧基苯甲酰胺 1 与多取代丙二烯的有效 Rh(III) 催化逐步邻位烯丙基化。这种涉及丙二烯的 CH 官能化是在非常温和的条件下(-20 °C 或室温)进行的,并且与环境空气和水分兼容,它可以应用于具有不同合成吸引力官能团的末端或内部丙二烯。已经实现了高效的轴向手性转移,产生了光学活性内酯。