The chemistry of organoborates. 9. A regiospecific and highly stereoselective construction of trisubstituted αβ-unsaturated ketones, tetrasubstituted αβ-unsaturated ketones and specifically protected 1,3-diketones from alkynyltrialkylborates
作者:Andrew Pelter、M. Eamon Colclough
DOI:10.1016/0040-4020(94)00953-r
日期:1995.1
fashion such that the dioxolanium group and the migrating group are on the same side of the new alkene intermediate. Hydrolysis of the intermediate yields Z-trisubstituted αβ-unsaturatedketones in which all three substituents have different origins and can be independently varied. Oxidation of the intermediates gives β-ketoacetals, which are regiospecifically protected 1,3-diketones. If the initial intermediates
(<i>E/Z</i>)-Furfurylalkenes from 2-Chloromethylfuran and Lithium Trialkylalkynylborates
作者:Li Nan-Sheng、Chen Yan、Deng Min-Zhi
DOI:10.1055/s-1991-26386
日期:——
Reaction of 2-chloromethylfuran with the nucleophile lithium trialkylalkynylborate under mild conditions, followed by protonation gives (E/Z)-furfurylalkenes with moderate E-stereoselectivity (E/Z = 3:1 to 7:1) and good yield.
Novel uncatalysed Michael reactions of lithium trialkylalkynylborates with alkylidenemalonates and alkylideneacetoacetates.
作者:Andrew Pelter、J.Madhusudhana Rao
DOI:10.1016/0040-4039(81)80155-4
日期:1981.1
Alkynylborates and alkylidenemalonates and alkylideneacetoacetates undergo unusual Michael reactions which involve migration of alkyl groups from boron to carbon, to yield products of synthetic value.
The stereoselective allylation of lithium trialkylalkynylborates by allyl carbonate in the presence of Pd(PPh3)4
作者:Yan Chen、Nan-Sheng Li、Min-Zhi Deng
DOI:10.1016/s0040-4039(00)97373-8
日期:1990.1
The reaction of allylcarbonate with lithiumtrialkylalkynylborates catalysed by Pd(PPh3)4, affords 1,4-alkadienes in good yields and high stereoselectivity.
Alkylation and protonation of alkynyltrialkylborate salts-a new general method for the preparation of ketones
作者:Andrew Pelter、C. R. Harrison、D. Kirkpatrick
DOI:10.1039/c39730000544
日期:——
Terminal alkynes (R2CCH) may be converted into ketones (R2R3CHCOR1) by the alkylation or protonation of lithium lakynyltrialkylborate salts followed by oxidation, this being a general route to specifically substituted ketones and a major extension of alkyne chemistry.
末端炔烃(R 2 C CH)可以通过烷基三烷基硼酸锂盐的烷基化或质子化反应再转化为酮(R 2 R 3 CHCOR 1),这是通向特定取代的酮的一般路线,也是炔烃化学的主要延伸。