Design and synthesis of condensed thienocoumarins by Suzuki–Miyaura reaction/lactonization tandem protocol
摘要:
A concise and efficient approach to a series of chromen-4-ones with fused thiophene ring has been developed using the Suzuki-Miyaura reaction of bromothiophene-2- and 3-carboxylates with 2-methoxyboronic acids and subsequent cyclization of prepared alkyl (2-methoxy)aryl thiophene-2- and 3-carboxylates under the action of BBr3/KOtBu. Starting bromothiophenes are easily obtained from corresponding commercially available aminothiophenes by diazotization/bromination reaction. (C) 2012 Elsevier Ltd. All rights reserved.
Rh(<scp>iii</scp>)-catalyzed oxidative C–H bond arylation with hydroquinones: sustainable synthesis of dibenzo[b,d]pyran-6-ones and benzo[d]naphtho[1,2-b]pyran-6-ones
An efficient Rh(iii)-catalyzed C–H bond arylation with phenol derivatives was developed for the direct and sustainable synthesis of dibenzo[b,d]pyran-6-ones and benzo[d]naphtho[1,2-b]pyran-6-ones.
Rh(<scp>iii</scp>)-Catalyzed sequential <i>ortho</i>-C–H oxidative arylation/cyclization of sulfoxonium ylides with quinones toward 2-hydroxy-dibenzo[<i>b,d</i>]pyran-6-ones
作者:Yaqun Dong、Jin-Tao Yu、Song Sun、Jiang Cheng
DOI:10.1039/d0cc00176g
日期:——
d ortho-C–H functionalization of sulfoxoniumylides followed by intramolecular annulation reactions with quinones was described, where the carbonyl in sulfoxoniumylides served as a chelation group. This protocol leads to the efficient formation of 2-hydroxy-6H-benzo[c]chromen-6-one derivatives, proceeding with the cleavage of the C(O)–S bond in sulfoxoniumylides. This protocol featured high chemo-selectivity
描述了铑(III)催化的亚砜基吡啶的邻位C-H官能化,然后与醌进行分子内环化反应,其中亚砜基吡啶中的羰基用作螯合基团。该方案导致2-羟基-6 H-苯并[ c ]铬n-6-one衍生物的有效形成,并进行了亚砜基磺酸盐中C(O)-S键的裂解。该协议具有高化学选择性和官能团耐受性的特点,其中亚硫酸sulf盐作为芳酰基源。
Facile synthetic route to benzo[<i>c</i>]chromenones and thieno[2,3-<i>c</i>]chromenones
作者:Olga Ya. Shyyka、Roman L. Martyak、Mykola A. Tupychak、Nazariy T. Pokhodylo、Mykola D. Obushak
DOI:10.1080/00397911.2017.1380833
日期:2017.12.17
two-step procedure for the synthesis of fused chromenone derivatives was developed. Reduction of the obtained in the Meerwein arylation reaction aryl- and thienylquinones allowed to construct 6H-benzo[c]chromene-6-ones and 4H-thieno[2,3-c]chromen-4-one in a more cost- and time-effective manner in comparison with already known methods. The obtained products have provided a new entry to chromenone derivatives
A concise and efficient approach to a series of chromen-4-ones with fused thiophene ring has been developed using the Suzuki-Miyaura reaction of bromothiophene-2- and 3-carboxylates with 2-methoxyboronic acids and subsequent cyclization of prepared alkyl (2-methoxy)aryl thiophene-2- and 3-carboxylates under the action of BBr3/KOtBu. Starting bromothiophenes are easily obtained from corresponding commercially available aminothiophenes by diazotization/bromination reaction. (C) 2012 Elsevier Ltd. All rights reserved.