The visible-light-induced acylation/cyclization of alkynoates with acyl oximes for the construction of 3-acylcoumarins
作者:Quan Zhou、Fang-Ting Xiong、Pu Chen、Bi-Quan Xiong、Ke-Wen Tang、Yu Liu
DOI:10.1039/d1ob01568k
日期:——
by the visible-light-induced acylation/cyclization of alkynoates with various acyl oximecompounds in acetonitrile. The difunctionalization of carbon–carbon triple bonds precedes the generation of iminyl radicals, which is followed by the formation of acyl radicals. The acyl radicals then attack the carbon–carbon triple bonds, followed by 5-exo-trig cyclization and 1,2-ester migration. This strategy
A convenient and efficient visible-light-induced tandem acylation/cyclization of N-propargylindoles with aryl- or alkyl-substituted acyl oxime esters for the synthesis of 2-acyl-substituted 9H-pyrrolo[1,2-a]indoles under transition-metal-free conditions, which proceeds via nitrogen-centered radical-mediated cleavage of the C–C σ-bond in acyl oxime esters, is established. The aryl or alkylacyl radicals
N-炔丙基吲哚与芳基-或烷基-取代的酰基肟酯的方便有效的可见光诱导串联酰化/环化,用于合成2-酰基-取代的9 H-吡咯并[1,2- a ]吲哚过渡建立了无金属条件,该条件通过氮中心自由基介导的酰基肟酯中 C-C σ 键的裂解进行。来自酰基肟酯的芳基或烷基酰基自由基攻击N-炔丙基吲哚中的 C-C 三键,然后进行分子内环化/异构化。
Visible-Light-Induced Dual Acylation of Alkenes for the Construction of 3-Substituted Chroman-4-ones
structural skeletons. Herein, we report a visible-light-induced dual acylation of alkenes for constructing 3-substituted chroman-4-ones, which undergoes a radical tandem cyclization reaction through carbon–carbon bond cleavage of oxime esters by a nitrogen-centered radical strategy. A series of 3-substituted chroman-4-ones were prepared with up to 86% yield.
A nitrogen-centered radical strategy for the preparation of 3-acylated spiro[4,5]trienones via visible-light-mediated acylation/ipso-cyclization of alkynes with acyl oxime esters is reported. The alkyl- and aryl-substituted acylradicals, which generate from the cleavage of carbon-carbon σ-bonds in acyl oxime esters via nitrogen-centered radical pathway, attack the carbon-carbon triple bonds in propiolamides
The effect of acyl substituents on the α-effect: contrasting α-effect profiles for reactions of 4-nitrophenyl substituted benzoates with neutral and anionic nucleophiles
作者:Ik-Hwan Um、Hyun-Joo Han、Eun-Kyung Chung
DOI:10.1016/s0040-4039(01)01719-1
日期:2001.11
The magnitude of the α-effect for reactions of 4-nitrophenyl substituted benzoates with a pair of anionicnucleophiles is independent of the electronic nature of the acyl substituent, while the one for the corresponding reactions with a pair of neutral nucleophiles increases as the acyl substituent changes from a strong electron withdrawing substituent to electron donating ones.