One, two, three, four: A copper(I)–phosphine complex catalyzes the diborylation of alkynes and arynes, and the tri‐ or tetraborylation of propargyl ethers (see scheme; pin=pinacolato). In the latter cases, the CO bond(s) as well as the CC bond are borylated in one pot. Furthermore, a diborylation product serves as an intermediate in the efficient synthesis of ortho‐terphenyls with pharmacological
Palladium-catalyzed double cross-coupling reaction of 1,2-bis(pinacolatoboryl)alkenes and -arenes with 2,2′-dibromobiaryls: annulative approach to functionalized polycyclic aromatic hydrocarbons
This study demonstrates that the doublecross-coupling reaction of 1,2-bis(pinacolatoboryl)alkenes and -arenes with 2,2′-dibromobiaryls proceeds smoothly with the aid of a catalytic amount of Pd(PPh3)4 in the presence of excess base to give a variety of polycyclic aromatic hydrocarbons, such as phenanthrenes, [5]helicene, dithienobenzenes, triphenylenes, dibenzo[g,p]chrysenes, and triphenyleno[1,2-b:4
这项研究表明,在催化量的Pd(PPh 3)4存在下,1,2-双(频哪醇硼基)烯烃和-芳烃与2,2'-二溴联芳基的双交叉偶联反应可以顺利进行。过量的碱可得到各种多环芳烃,例如菲,[5]螺旋烯,二硫代苯,三苯撑,二苯并[ g,p ],和三苯并[1,2- b:4,3- b ']二噻吩好到高产。值得注意的是,使用2,2'-二溴八氟联苯作为亲电试剂的环化反应提供了否则难以合成的八氟菲和半氟化二苯并[ g,p] chrysenes高产。
Base-catalyzed diborylation of alkynes: synthesis and applications of cis-1,2-bis(boryl)alkenes
作者:Zhijie Kuang、Guoliang Gao、Qiuling Song
DOI:10.1007/s11426-018-9344-4
日期:2019.1
An efficient, transition-metal free, and practical approach to cis-bis(boryl)alkenes from various alkynes was disclosed in the presence of a catalytic amount of K2CO3 under mild conditions. Meanwhile, tetrasubstituted alkenes and phenanthrene derivatives were readily constructed from the target diborylalkenes via Suzuki-Miyaura cross coupling.
公开了在温和条件下在催化量的K 2 CO 3存在下从各种炔烃制得的有效,无过渡金属且实用的方法来从各种炔烃中制备顺式-双(硼基)烯烃。同时,通过铃木-宫浦(Suzuki-Miyaura)交叉偶合容易地由目标二硼烷基烯烃构建四取代的烯烃和菲衍生物。
Dehydrogenative Diboration of Alkynes Catalyzed by Ir/CO/tBuNC System
作者:Qingheng Lai、Oleg V. Ozerov
DOI:10.1016/j.jorganchem.2020.121614
日期:2021.1
dehydrogenative diboration (DHDB) of alkyne with HBpin was achieved using [Ir(COD)Cl]2 and other related Ir precursors under CO atmosphere. The selectivity for DHDB over hydroboration was higher in less polar solvents and under higher CO pressure. It was further improved when catalytic amount of tBuNC was added to the reaction. It was possible to achieve DHDB of both terminal and internal alkynes with selectivity
N-Alkoxypyrazoles as biomimetics for the alkoxyphenyl group in tamoxifen
作者:Martin Wenckens、Palle Jakobsen、Per Vedsø、Per Olaf Huusfeldt、Birgitte Gissel、Marianne Barfoed、Bettina Lundin Brockdorff、Anne E Lykkesfeldt、Mikael Begtrup
DOI:10.1016/s0968-0896(02)00566-7
日期:2003.4
The preparation of a series of novel analogues of the selective antiestrogen tamoxifen is reported. 1Z-alkoxyphenyl group in tamoxifen has been replaced by a N-alkoxypyrazole, while functionalised phenyl groups or heteroaromatics were introduced at the 2Z-position using sequential Suzuki cross coupling of 1,2-(bis)borylpinacol 1-phenylbutene with 4- or 5-iodo-1-N,N-dimethylaminoethyl or propyl-pyrazoles. Approximately 50 tamoxifen analogues were obtained and tested in an estrogen receptor (ERalpha) affinity assay. Several compounds exhibited binding affinities 2-5-fold lower than tamoxifen. Dose-response experiments with six selected compounds were carried out using two different human breast cancer cell lines, MCF-7 and the tamoxifen resistant cell line MCF-/TAM(R)-1. Both cell lines exhibited growth inhibition upon treatment with the tamoxifen analogues. Co-treatment of the cells, with estradiol and the individual compounds, were also performed. The results indicated that the observed growth inhibitory effect was mediated by the ERalpha. Analogues of the potent antiestrogen 4-hydroxytamoxifen (4-OHT) were synthesised where the 1E-4-hydroxyphenyl was replaced by a 1-hydroxypyrazol-4-yl group. However, modest growth inhibition of MCF-7 cells was observed upon treatment with these analogues. In contrast, 1Z-, 2Z-ringclosed tamoxifen analogue (59) was shown to possess antiproliferative effects on MCF-7 and MCF-/TAM(R)-1 cells in lower doses than tamoxifen. (C) 2003 Elsevier Science Ltd. All rights reserved.