Syntheses and Properties of Medium-Sized Metacyclophanediynes
摘要:
The syntheses of [11]metacyclophane-2,9-diyne (3), [4.4]metacyclophane-2,12-diyne (4), [4.4]orthometacyclophane-2,12-diyne (5), (Z)-[10]metacyclophane-5-ene-2,8-diyne (6), [10]metacyclophane-2,8-diyne (7), and 5-isopropylidene[9]metacyclophane-2,7-diyne (8) have been achieved. The systems could be stabilized by protecting the triple bonds in 3-8 with the Co-2(CO)(6) moiety. PE spectroscopic investigations of 3 and 6-8 gave no clear-cut evidence for homoconjugative interactions among the pi fragments. The triple bonds in 3-8 could be transformed into the corresponding cis double bands by applying 2-5 molar equiv of Schwartz's reagent (28). Treatment of 3, 4, and ? with t-BuOK allows the transformation of the propargylic moieties into allenic moieties, whereas the same treatment of 5 and 6 transforms the 2-butynyl bridges into 1,3-butadiene bridges, giving rise to several isomers. The structural assignments of 3-8 and their reaction products are based an their spectroscopic properties.
Direct Synthesis of 1-Arylprop-1-ynes with Calcium Carbide as an Acetylene Source
作者:Lei Gao、Zheng Li
DOI:10.1055/s-0037-1610718
日期:2019.8
A simple method is described for the synthesis of 1-arylprop-1-ynes directly from aromatic aldehyde p-tosylhydrazones by using calcium carbide as an acetylene source. The salient features of this protocol are its use of a readily available and easily handled source of acetylene, its operational simplicity, its high yield, and its broad substrate scope.
A regioselectivity switch in Pd-catalyzed hydroallylation of alkynes
作者:Ding-Wei Ji、Yan-Cheng Hu、Hao Zheng、Chao-Yang Zhao、Qing-An Chen、Vy M. Dong
DOI:10.1039/c9sc01527b
日期:——
Through rational evaluation of ligands and promoters, the reactivity of a key Pd(ii) species towards transmetalation or β-H elimination is manipulated.
通过对配体和促进剂的理性评估,可以操控关键的Pd(II)物种对于金属转移或β-H消除的活性。
Synthesis of diarylenynes by olefination of 1-arylpropyne with arylaldehyde and their optical properties
A new synthetic protocol of 1-arylpropyne was developed by taking advantage of 1-(diphenylphosphoryl)propyne as propyne equivalent in Sonogashira coupling: consecutive subjection of phosphorylpropyne to t-BuOK and to aryl halides in the presence of Pd and Cu catalysts afforded the corresponding 1-arylpropynes. The following olefination of the 1-arylpropyne with aldehyde provided the corresponding diarylenyne. When the enynes thus obtained were irradiated with UV light, they showed strong emission in organic solvents and in the solid states. In solution, Ph2N-substituted enynes exhibited remarkable solvatofluorochromism, and Lippert-Mataga plot analysis demonstrated that they undergo the larger polarization in the excited states than in the ground states. (C) 2016 Elsevier Ltd. All rights reserved.
Miljanić, Ognjen Š.; Vollhardt, K. Peter C.; Whitener, Glenn D., Synlett, 2003, # 1, p. 29 - 34
作者:Miljanić, Ognjen Š.、Vollhardt, K. Peter C.、Whitener, Glenn D.
DOI:——
日期:——
Syntheses and Properties of Medium-Sized Metacyclophanediynes
作者:Matthias Ramming、Rolf Gleiter
DOI:10.1021/jo970327r
日期:1997.8.1
The syntheses of [11]metacyclophane-2,9-diyne (3), [4.4]metacyclophane-2,12-diyne (4), [4.4]orthometacyclophane-2,12-diyne (5), (Z)-[10]metacyclophane-5-ene-2,8-diyne (6), [10]metacyclophane-2,8-diyne (7), and 5-isopropylidene[9]metacyclophane-2,7-diyne (8) have been achieved. The systems could be stabilized by protecting the triple bonds in 3-8 with the Co-2(CO)(6) moiety. PE spectroscopic investigations of 3 and 6-8 gave no clear-cut evidence for homoconjugative interactions among the pi fragments. The triple bonds in 3-8 could be transformed into the corresponding cis double bands by applying 2-5 molar equiv of Schwartz's reagent (28). Treatment of 3, 4, and ? with t-BuOK allows the transformation of the propargylic moieties into allenic moieties, whereas the same treatment of 5 and 6 transforms the 2-butynyl bridges into 1,3-butadiene bridges, giving rise to several isomers. The structural assignments of 3-8 and their reaction products are based an their spectroscopic properties.