Synthetic chlorins bearing auxochromes at the 3- and 13-positions.
Synthetic chlorins bearing auxochromes at the 3- and 13-positions.
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在 3 位和 13 位带有助色团的合成二氢卟酚。
DOI：
10.1021/jo060208o
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发表时间：
2006
期刊：
影响因子：
--
通讯作者：
Lindsey,JonathanS
中科院分区：
文献类型：
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作者：
Laha,JoydevK;Muthiah,Chinnasamy;Taniguchi,Masahiko;McDowell,BrianE;Ptaszek,Marcin;Lindsey,JonathanS
在大环的3-和13-位具有不同助色剂的合成二氢卟酚是有价值的目标，因为它们与具有3-乙烯基和13-酮基的叶绿素a和b相似。一个从头路线已被利用，以构建九个锌二氢卟酚轴承取代基在3-和13-位和两个基准锌二氢卟酚缺乏这样的取代基。二氢卟酚在空间上是不拥挤的，并且具有（1）在还原的吡咯啉环中的偕二甲基，（2）在3位的H、乙酰基、三异丙基甲硅烷基乙炔基（TIPS-乙炔基）或乙烯基，（3）在13位的H、乙酰基或TIPS-乙炔基，和（4）在10位的H或均三甲苯基。13-取代二氢卟酚的合成依赖于8，9-二溴-1-甲酰基二吡咯甲烷（东半部分）和2，3，4，5-四氢-1，3，3-三甲基二吡咯（西半部分）在p-TsOH·H2O催化下的缩合反应，然后通过金属介导的氧化环化反应得到13-溴二氢卟酚。溴-或TIPS-乙炔基-取代的西半部分的类似使用提供了获得3-取代的二氢卟酚的途径。通过Pd偶联进一步转化3-溴、13-溴或3，13-二溴二氢卟酚，以引入乙烯基（经由三丁基乙烯基锡）、TIPS-乙炔基（经由TIPS-乙炔）或乙酰基（经由三丁基（1-乙氧基乙烯基）锡，随后酸水解）。在10-均三甲苯基取代的锌二氢卟酚中，3-乙烯基、13-TIPS-乙炔基、3-TIPS-乙炔基、13-乙酰基、3，13-双（TIPS-乙炔基）、3-TIPS-乙炔基-13-乙酰基或3，13-二乙酰基逐渐引起（1）B带的最大吸收红移（405 - 436 nm）和Qy带（606 - 662 nm）的强度增加，（2）Qy带的强度相对增加（IB/IQ= 4.2 - 1.5），以及（3）荧光量子产率Φf（0.059 - 0.29）增加。带有3-TIPS-乙炔基-13-乙酰基或3，13-二乙酰基的锌二氢卟酚具有许多类似于叶绿素a或其锌类似物的光谱性质。两者合计，这项研究提供了获得微调二氢卟酚光谱研究和不同的应用。
Synthetic chlorins bearing diverse auxochromes at the 3- and 13-positions of the macrocycle are valuable targets given their resemblance to chlorophyllsaandb, which bear 3-vinyl and 13-keto groups. A de novo route has been exploited to construct nine zinc chlorins bearing substituents at the 3- and 13-positions and two benchmark zinc chlorins lacking such substituents. The chlorins are sterically uncongested and bear (1) a geminal dimethyl group in the reduced pyrroline ring, (2) a H, an acetyl, a triisopropylsilylethynyl (TIPS-ethynyl), or a vinyl at the 3-position, (3) a H, an acetyl, or TIPS-ethynyl at the 13-position, and (4) a H or a mesityl at the 10-position. The synthesis of the 13-substituted chlorins relied onp-TsOH·H2O-catalyzed condensation of an 8,9-dibromo-1-formyldipyrromethane (eastern half) and 2,3,4,5-tetrahydro-1,3,3-trimethyldipyrrin (western half), followed by metal-mediated oxidative cyclization, affording the 13-bromochlorin. Similar use of a bromo- or TIPS-ethynyl-substituted western half provided access to 3-substituted chlorins. A 3-bromo, 13-bromo, or 3,13-dibromochlorin was further transformed by Pd-coupling to introduce the vinyl group (via tributylvinyltin), TIPS-ethynyl group (via TIPS-acetylene), or acetyl group (via tributyl(1-ethoxyvinyl)tin, followed by acidic hydrolysis). In the 10-mesityl-substituted zinc chlorins, the series of substituents, 3-vinyl, 13-TIPS-ethynyl, 3-TIPS-ethynyl, 13-acetyl, 3,13-bis(TIPS-ethynyl), 3-TIPS-ethynyl-13-acetyl, or 3,13-diacetyl, progressively causes (1) a redshift in the absorption maximum of the B band (405−436 nm) and the Qyband (606−662 nm), (2) a relative increase in the intensity of the Qyband (IB/IQ= 4.2−1.5), and (3) an increase in the fluorescence quantum yield Φf(0.059−0.29). The zinc chlorins bearing a 3-TIPS-ethynyl-13-acetyl or a 3,13-diacetyl group exhibit a number of spectral properties resembling those of chlorophyllaor its zinc analogue. Taken together, this study provides access to finely tuned chlorins for spectroscopic studies and diverse applications.