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。
C–H Bond Functionalization of Benzoic Acid: Catalytic Synthesis of 2-Hydroxy-6<i>H</i>-benzo[<i>c</i>]chromen-6-ones Using (Cp*IrCl<sub>2</sub>)<sub>2</sub>
作者:Kristi L. Engelman、Yuee Feng、Elon A. Ison
DOI:10.1021/om200343b
日期:2011.9.12
Catalytic H/D exchangereactions of benzene and benzoic acid with deuterated solvents have been studied using (Cp*IrCl2)2. A 1:1 mixture of D2O/CD3OD produced the highest turnover numbers for benzene. High levels of deuterium incorporation into benzoic acid were observed only when sodium acetate was added to the reaction mixture. Attempts at producing hydroxybenzoic acid by catalytic C–H functionalization
使用(Cp * IrCl 2)2研究了苯和苯甲酸与氘代溶剂的催化H / D交换反应。D 2 O / CD 3 OD的1:1混合物产生的苯的周转率最高。仅当将乙酸钠加入到反应混合物中时,才观察到高水平的氘掺入苯甲酸中。通过苯甲酸与苯醌催化CH-H官能化生产羟基苯甲酸的尝试未成功。取而代之的是2-羟基-6 H-苯并[ c分离出] chromen-6-one作为主要产物。针对该官能化反应分析了一系列取代的苯甲酸。初步的机理研究表明,苯并二氢吡喃酮是通过苯甲酸的C–H键活化,然后将苯醌插入到铱—碳键中而形成的。
Rh(<scp>iii</scp>)-catalyzed synthesis of dibenzo[<i>b</i>,<i>d</i>]pyran-6-ones from aryl ketone <i>O</i>-acetyl oximes and quinones <i>via</i> C–H activation and C–C bond cleavage
作者:Wei Yang、Haonan Zhang、Yu Liu、Cuiman Tang、Xiaohui Xu、Jiaqi Liu
DOI:10.1039/d2ra02074b
日期:——
A redox-neutral synthesis of dibenzo[b,d]pyran-6-ones from aryl ketone O-acetyl oximes and quinones has been realized via Rh(III)-catalyzedcascade C–H activation annulation. A possible Rh(III)–Rh(V)–Rh(III) mechanism involving an unprecedented β-C elimination step was proposed.
通过Rh( III )催化级联C-H活化环化,实现了从芳基酮O-乙酰肟和醌氧化还原中性合成二苯并[ b , d ]吡喃-6-酮。提出了一种可能的 Rh( III )–Rh( V )–Rh( III ) 机制,涉及前所未有的 β-C 消除步骤。
205. Cannabis indica. Part III. The synthesis of dibenzopyran derivatives, including an isomer of cannabinol