Expanded Scope of Synthetic Bacteriochlorins via Improved Acid Catalysis Conditions and Diverse Dihydrodipyrrin-Acetals
作者:Michael Krayer、Marcin Ptaszek、Han-Je Kim、Kelly R. Meneely、Dazhong Fan、Kristen Secor、Jonathan S. Lindsey
DOI:10.1021/jo9025572
日期:2010.2.19
conditions has afforded diverse bacteriochlorins (e.g., bearing alkyl/ester, aryl/ester, diester, and no substituents) in a few days from commercially available starting materials. Consideration of the synthetic steps and yields for formation of the dihydrodipyrrin-acetal and bacteriochlorin underpins evaluation of synthetic plans for early installation of bacteriochlorin substituents via the dihydrodipyrrin-acetal
细菌氯霉素由于在近红外光谱区域具有强吸收性,因此成为各种光化学研究的诱人候选物。用于二氢联吡啶醛缩醛(在吡咯啉环中带有双甲基二甲基基团)的自缩合的现有酸催化条件[BF 3 ·O(Et)2在室温下在CH 3 CN中]通常提供三个大环的混合物:预期的5-甲氧基细菌氯霉素(MeOBC型),5-未取代的细菌氯霉素(HBC型)和游离碱B,D-四氢脱氢corrin(TDC型)。这里,> 20个氨基酸的广泛的调查确定了四个有前途的酸催化条件,将TMSOTf / 2,6-二-叔CH 2 Cl 2中的叔丁基吡啶室温下最吸引人的是,由于形成了5-甲氧基细菌氯霉素作为唯一的大环,而与二氢联吡啶-乙缩醛中的吡咯取代基(吸电子,供电子或无取代基)无关。按照标准路线制备了十一种新的二氢二吡喃-乙缩醛。新的酸催化条件的应用在几天内从商购可得的起始原料中获得了多种细菌绿素(例如,带有烷基/酯,芳基/酯,二酯和无取代基)。