DABCO-catalyzed formation of 4-methoxy-1,3-dioxolan-2-ones and their synthetic applications in the aromatic electrophilic substitution
摘要:
DABCO is a very effective catalyst in the formation of 4-methoxy-1,3-dioxolan-2-ones 10 from the corresponding alpha-carbonatoaldehydes 8 intermediates. The Friedel-Crafts reaction pathway of the cyclic carbonate 10 is dependent on the electron density of the aromatic nucleophiles. (C) 2008 Elsevier Ltd. All rights reserved.
受铑催化羧酸经济向丙二烯中添加羧酸的机理研究的启发,已开发出铑催化的不同亲核试剂与消旋烯丙基碳酸酯的动态动力学不对称烯丙基化反应。在中性条件下可以获得很高的区域选择性和对映选择性,此外,化学选择性可以通过不同的二膦配体来控制。(R,R)-QuinoxP *导致酚的选择性O-烯丙基化,而当嵌入(S,S)-DIOP作为配体时,2-萘酚首次以高对映选择性被邻-C-烯丙基化。为此,羟基吡啶可以通过Rh I /(S)-DTBM-Segphos的中间体与先前报道的对丙二烯的原子经济加成反应相同。
Rh(I)/Bisoxazolinephosphine-Catalyzed Regio- and Enantioselective Allylic Substitutions
作者:Wen-Bin Xu、Samir Ghorai、Wenyu Huang、Changkun Li
DOI:10.1021/acscatal.0c00712
日期:2020.4.17
Rhodium(I)/bisoxazolinephosphine combination has been developed as a general catalyst to achieve the dynamic kinetic asymmetric allylation of a variety of nitrogen, carbon, oxygen, and sulfur pronucleophiles from branched racemic allylic carbonates. Exclusive branch-selectivity and up to 99% enantiomeric excess could be obtained under neutral conditions. Linear allylic substrates (both Z and E) could
Regio- and Enantioselective Allylic Alkylation of Terminal Alkynes by Synergistic Rh/Cu Catalysis
作者:Wen-Yu Huang、Chun-Hua Lu、Samir Ghorai、Bing Li、Changkun Li
DOI:10.1021/jacs.0c08283
日期:2020.9.9
A highly branch- and enantioselective 1,4-enynes synthesis from readily available terminalalkynes and racemic allylic carbonates by Sonogashira type synergistic Rh and Cu catalysis under neutral conditions has been developed. Aliphatic and aromatic terminalalkynes with various functional groups could be used directly. An inner-sphere reductive elimination C(sp)-C(sp3) bond formation mechanism is
在中性条件下,Sonogashira 型协同 Rh 和 Cu 催化从容易获得的末端炔烃和外消旋烯丙基碳酸酯合成高度支化和对映选择性的 1,4-烯炔。可以直接使用具有各种官能团的脂肪族和芳香族末端炔烃。化学计量反应支持内球体还原消除 C(sp)-C(sp3) 键形成机制。
DABCO-catalyzed formation of 4-methoxy-1,3-dioxolan-2-ones and their synthetic applications in the aromatic electrophilic substitution
作者:Yung-Son Hon、Chen-Yi Kao
DOI:10.1016/j.tetlet.2008.09.173
日期:2009.2
DABCO is a very effective catalyst in the formation of 4-methoxy-1,3-dioxolan-2-ones 10 from the corresponding alpha-carbonatoaldehydes 8 intermediates. The Friedel-Crafts reaction pathway of the cyclic carbonate 10 is dependent on the electron density of the aromatic nucleophiles. (C) 2008 Elsevier Ltd. All rights reserved.
Rhodium-Catalyzed Dynamic Kinetic Asymmetric Allylation of Phenols and 2-Hydroxypyridines
作者:Changkun Li、Bernhard Breit
DOI:10.1002/chem.201603532
日期:2016.10.4
dynamic kinetic asymmetric allylation of different nucleophiles with racemic allylic carbonates has been developed. High regio‐ and enantioselectivities can be obtained under neutral conditions and, furthermore, the chemoselectivities can be controlled by different diphosphine ligands. (R,R)‐QuinoxP* leads to selective O‐allylation of phenols, whereas when embedding (S,S)‐DIOP as the ligand, 2‐naphthol
受铑催化羧酸经济向丙二烯中添加羧酸的机理研究的启发,已开发出铑催化的不同亲核试剂与消旋烯丙基碳酸酯的动态动力学不对称烯丙基化反应。在中性条件下可以获得很高的区域选择性和对映选择性,此外,化学选择性可以通过不同的二膦配体来控制。(R,R)-QuinoxP *导致酚的选择性O-烯丙基化,而当嵌入(S,S)-DIOP作为配体时,2-萘酚首次以高对映选择性被邻-C-烯丙基化。为此,羟基吡啶可以通过Rh I /(S)-DTBM-Segphos的中间体与先前报道的对丙二烯的原子经济加成反应相同。