1 H-吡唑并[3,4- b ]喹喔啉的区域特异性合成新方法–有机光电器件的潜在材料,以及对旧方案的修订
摘要:
使用一种新的合成途径制备了一系列6-取代的1,3-二苯基-1H-吡唑并[3,4- b ]喹喔啉:将适当的5-(邻硝基苯基)-吡唑与草酸亚铁或三苯基膦。该方法的主要优点是,与吡唑并[3,4- b ]喹喔啉合成的旧方案相反,该方法允许将取代基引入碳环而不形成异构体。吡唑环也可以进行一定程度的修饰。此外,我们提出了一种新的机制,据报道,邻苯二酚之间的缩合反应可用于最古老的吡唑并[3,4- b ]喹喔啉合成。-苯二胺和3,4-吡唑啉-5-二酮。
The catalytic enantioselective diorganozinc additions to cyclic diketones including pyrazolin‐4,5‐diones and isatins have been developed. In the presence of morpholine‐containing chiral amino alcohol ligand, the corresponding chiral cyclic tertiary alcohols were produced in good to excellent yields (up to 97 %) and enantioselectivities (up to 95 % ee). The notable feature of this protocol includes
reactivity of a series of novel pyrazole-4,5-dione derivatives in the organocatalytic Friedel–Crafts reaction with various substituted indoles has been tested. The disclosed procedure catalyzed by a cinchona alkaloid derivative allows the conjugation of two very important aza-heterocyclic scaffolds to generate a new class of indolylpyrazolones bearing a tetrasubstituted stereocenter in excellent yields
New Synthesis of Pyrazolo[3,4-<i>b</i>][1,4,5]benzothiadiazepine, -[1,4,5]benzoxadiazepine, -[1,4,5]benzotriazepine and Pyrazolo[3,4-<i>b</i>]quinoxaline Derivatives
作者:Eman A. El-Rady
DOI:10.1002/jccs.200400129
日期:2004.8
New pyrazolo[3,4-b][1,4,5]benzothiadiazepine and its analogues 3 have been obtained by reaction of 4-nitrosopyrazoles 1 with 2-aminothiophenol 2a and its analogues 2b,c. Under fused conditions, dipyrazolyl derivatives 7a was obtained with a trace amount of quinoxaline 5a. On the other hand, 5b and 7b were obtained in equal amounts. A proposed pathway is presented.
N‐Boc ketimines derived from pyrazolin‐5‐ones were explored to develop an unprecedented domino aza‐Friedel–Crafts/N,O‐acetalization reaction with 2‐naphthols. The novel method requires a catalyst loading of only 0.5 mol % of a bifunctional squaramide catalyst, is scalable to gram amounts, and provides a new series of furanonaphthopyrazolidinone derivatives bearing two vicinal tetra‐substituted stereogenic
A new series of N-Boc ketimines derived from pyrazolin-5-ones have been used as electrophiles in asymmetric Mannichreactions with pyrazolones. The amino-bis-pyrazolone products are obtained in excellent yields and stereoselectivities by employing a very low loading of 1 mol % of a bifunctional squaramide organocatalyst. Depending on the substitution at position 4 of the pyrazolones, the new protocol