Metal-Free Catalytic Reductive Cleavage of Enol Ethers
作者:Karina Chulsky、Roman Dobrovetsky
DOI:10.1021/acs.orglett.8b02932
日期:2018.11.2
In contrast to the well-known reductivecleavage of the alkyl–O bond, the cleavage of the alkenyl–O bond is much more challenging especially using metal-free approaches. Unexpectedly, alkenyl–O bonds were reductively cleaved when enol ethers were reacted with Et3SiH and a catalytic amount of B(C6F5)3. Supposedly, this reaction is the result of a B(C6F5)3-catalyzed tandem hydrosilylation reaction and
与众所周知的烷基-O键的还原裂解相反,烯基-O键的裂解更具挑战性,尤其是使用无金属方法时。出乎意料的是,当烯醇醚与Et 3 SiH和催化量的B(C 6 F 5)3反应时,烯基-O键被还原性裂解。据推测,该反应是B(C 6 F 5)3催化的串联氢化硅烷化反应和硅辅助的β-消除的结果。基于实验和密度泛函理论(DFT)计算,提出了这种裂解反应的机理。
The wittig rearrangement as a practical method for aldehyde synthesis
作者:Manfred Schlosser、Sven Strunk
DOI:10.1016/s0040-4020(01)80095-8
日期:1989.1
If the rearrangement of metalated allyl ethers 2 (or 4) is accomplished in the presence of potassium tert-butoxide, primary alkyl groups preferentially migrate to the unsubstituted allylic terminus (γ-position). Enolates 7 and 1-vinylalcoholates 6 (by alkyl migration to the α-position, adjacent to the oxygen atom) are produced in an approximate ratio of 9:1. Because of the endo-configuration of their
The action of triethylsilane on α-ethylenic aldehydes has been studied in the presence of two types of nickel catalysts as well as palladium on charcoal. Two phenomena can result: either 1,2 or 1,4 additions only, the trans-1,4 adduct being predominant, or a competition between these two additions and coupling reactions. A comparative regioselective and stereoselective study was carried out making