to the Lindsey procedure, to a series of octa- and dodeca-substituted porphyrins. This procedure, which consists of a palladium-catalysed oxidative alkoxycarbonylation of N-substituted dipropargylamine derivatives 1, works nicely for n-alkyl alcohols in the range C1 to C14. The thermotropic behaviour of this series of porphyrins (28 compounds) has been investigated using polarization microscopy, DSC
Living Cyclopolymerization of 1,6-Heptadiyne Derivatives Using Well-Defined Alkylidene Complexes: Polymerization Mechanism, Polymer Structure, and Polymer Properties
作者:Harold H. Fox、Michael O. Wolf、Richard O'Dell、Beatrice L. Lin、Richard R. Schrock、Mark S. Wrighton
DOI:10.1021/ja00086a016
日期:1994.4
Mo(NAr)(CHCMe[sub2]Ph)(OR[sub F6])[sub2] (1a; Ar = 2,6-i-Pr[sub2]C[sub 6]H[sub 3], OR[sub F6] = OCMe(CF[sub 3])[sub2]) as the initiator in 1,2-dimethoxyethane (DME). The polymers show a high degree of conjugation ([lambda][sub max] > 500 nm) and have narrow molecular weight distributions. Poly(2a) is soluble in most organic solvents (THF, C[sub 6]H[sub 6], toluene, CH[sub2]Cl[sub2], CHCl[sub 3], DME
Gold Catalysis: Products and Intermediates Obtained from N-Propargylcarboxamides Bearing Additional Substituents on Nitrogen
作者:A. Stephen K. Hashmi、Lise Molinari、Frank Rominger、Thomas Oeser
DOI:10.1002/ejoc.201100179
日期:2011.4
substrates with additional substituents on the nitrogen atom was investigated. Under aqueous conditions acyloxy-substituted allylammonium salts could selectively be obtained. Monitoring of the reactions by 1 H NMR spectroscopy indicated the presence of an intermediate. Then switching to anhydrous reaction conditions allowed the isolation and characterization of these intermediates, oxazoliniminium species
研究了几种炔丙酰胺底物与氮原子上的额外取代基的反应。在水性条件下,可以选择性地获得酰氧基取代的烯丙基铵盐。通过 1 H NMR 光谱监测反应表明存在中间体。然后切换到无水反应条件允许分离和表征这些中间体,恶唑啉鎓物种。在碱性条件下处理烯丙基铵盐导致酰基从氧原子转移到氮原子,这证明这些产物不是仅通过金催化的三键直接水合形成的,同时很好地解释了两个三键中只有一个的选择性一水合。
A high-activity cobalt-based MOF catalyst for [2 + 2 + 2] cycloaddition of diynes and alkynes: insights into alkyne affinity and selectivity control
作者:Fen Xu、Xiao-Ju Si、Xiao-Ning Wang、Hao-Dong Kou、Di-Ming Chen、Chun-Sen Liu、Miao Du
DOI:10.1039/c7ra12136a
日期:——
Heterogenous catalysis of [2 + 2 + 2] cycloaddition was firstly achieved by a low-cost, air-stable and reusable Co-MOF catalyst, affording structurally diverse functionalized benzenes under mild conditions with high efficiency and selectivity.
作者:Huimin Dai、Guifeng Liu、Xiaolei Zhang、Hong Yan、Changsheng Lu
DOI:10.1021/acs.organomet.6b00082
日期:2016.5.23
The reactions of the 16e half-sandwich complex CpCoS2C2B10H10 (1), diazo esters, and various 1,6-diynes (3a-i; PhN(CH2C-CH)(2), 4-Me-PhN(CH2C=CH)(2), 4-O-Me-PhN(CH2C=CH)(2), 4-F-PhN(CH2C=CH)(2), BzN(CH2=CH)(2), O(CH2=CH)(2), C(Ac)(2)(CH2C=CH)(2), N(CH2C=CH),, CH)(3) NH(CH2C=CH)N(CH2C=CH)(2) were investigated, in which two novel types of B-H activated products CpCoS2B10H9(CH2CO2Et) C5H3N(R) ( CH= CHCO2Et) (4a-c; R = Ph, 4 -Me-Ph, 4-OMe-Ph) and the key intermediate CpCoS2B10H9(CHCO2Me) (CH2CO2Me) (9) were isolated. 9 features a reactive Co-B bond, which triggers insertion of various 1,6-diynes to further lead to different final products. Substrates 3a-c are activated by the Co-B bond to produce o-carborane derivatives 4a-c which are functionalized by a cobalt-complexed eta(3)-pyrrolylmethyl group. The pyrrole ring is formed by in situ ring closure of 1,6-diynes. Control experiments and isolation of the intermediate CpCoS2B10H9(CHCO2Me)(CH2CO2Me)HC=CCH2N(4-Me-Ph)(CH2C=CH) (10) support the proposed mechanism concerning the formation of 4a-c analogues by oxidation. All of the new complexes were characterized by NMR, IR, elemental analysis, and mass spectrometry. The structures of 4a-6a and 9 were determined by single-crystal X-ray diffraction analysis as well.