Cut and join together: Chiral Copper phosphate complexes efficiently promoted a tandem sequence of deoxygenation/[4+2] cycloaddition reactions. This process gives access to various tetrahydroquinolines with threeconsecutive stereogenic centers in good yields with excellent diastereo‐and enantioselectivity.
Polyfunctionalized biaryls accessed by a one-pot nucleophilic aromatic substitution and sigmatropic rearrangement reaction cascade under mild conditions
作者:Dong-Dong Liang、Shen-Yi Guo、Shuo Tong、Mei-Xiang Wang
DOI:10.1016/j.tet.2021.131966
日期:2021.3
5]- or [3,3]-sigmatropicrearrangement reaction cascade. Under mild basic conditions, N-arylhydroxylamines reacted with o-activated fluoro (het)arenes to form N,O-diarylhydroxylamine intermediates which underwent spontaneously selective [5,5]-sigmatropicrearrangement reaction to produce diverse functionalized 4-amino-4′-hydroxy-1,1′-biaryls. A sequential SNAr reaction and [3,3]-sigmatropic rearrangement
一种实用的合成方法已被开发用于基于一个浅显一锅亲核芳香取代(S多官能化的联芳基Ñ AR)反应和[5,5] -或[3,3] -sigmatropic重排反应级联。在温和的碱性条件下,N-芳基羟胺与邻位活化的氟(杂)芳烃反应形成N,O-二芳基羟胺中间体,这些中间体自发地进行选择性[5,5]-σ重排反应,从而生成各种官能化的4-氨基-4'-羟基-1,1'-联芳基。在N之间发生了连续的S N Ar反应和[3,3]-σ重排-芳基羟胺和2-氟吡啶衍生物或4-氟苄腈,得到官能化的2-氨基-2'-羟基-1,1'-联芳基。作为宝贵且独特的组成部分,所得联芳基化合物可用于直接合成N 2,O 2-芳烃,咔唑,氮杂和重氮咔唑衍生物。
Rh(III)-Catalyzed C–H Cyclization of Arylnitrones with Diazo Compounds: Access to 3-Carboxylate Substituted<i>N</i>-Hydroxyindoles
作者:Yazhou Li、Jian Li、Xiaowei Wu、Yu Zhou、Hong Liu
DOI:10.1021/acs.joc.7b01393
日期:2017.9.1
Recently, N-hydroxyindole derivatives have received much interest because of their unique structural motif and various biological activities. In this study, we report the first example of a Rh(III)-catalyzed reaction of arylnitrones with α-diazoketoesters or α-diazodiketones to produce N-hydroxyindole derivatives. Intriguingly, we could build the N-hydroxyindole scaffold by blocking the cleavage of
Influence of the side-group at C=N bridging bond of bis-aryl Schiff bases on the wavelength of absorption maximum of ultraviolet absorption spectra
作者:Qingqing Luo、Chao-Tun Cao、Zhongzhong Cao、Chenzhong Cao
DOI:10.1002/poc.3550
日期:2016.8
methyl CH3 at carbon end and the CH=N(O) has a side‐group O atom at nitrogen end. In this work, a series of XPEAY and XPNY were synthesized, and their longest wavelength maximum λmax (nm) of ultravioletabsorptionspectra were measured. Then the change regularity of the νmax (cm‐1, νmax=1/λmax) of XPEAY and XPNY were investigated, and they were compared with that of XBAY (reported by ref.26). The results
Catalytic Diastereo- and Enantioselective Synthesis of 2-Imidazolinones
作者:Pablo Martínez-Pardo、Gonzalo Blay、Alba Escrivá-Palomo、Amparo Sanz-Marco、Carlos Vila、José R. Pedro
DOI:10.1021/acs.orglett.9b01244
日期:2019.6.7
Chiral cyclic ureas (2-imidazolinones) were prepared by the reaction of nitrones and isocyanoacetate esters using a multicatalytic system that combines a bifunctional Brønsted base–squaramide organocatalyst and Ag+ as a Lewis acid. The reaction could be achieved with a range of nitrones derived from aryl- and cycloalkylaldehydes with moderate diastereo- and good enantioselectivity. A plausible mechanism