A highly efficient approach to vanillin starting from 4-cresol
作者:Jian-An Jiang、Cheng Chen、Ying Guo、Dao-Hua Liao、Xian-Dao Pan、Ya-Fei Ji
DOI:10.1039/c4gc00003j
日期:——
A highly efficient approach to the famous flavor and fragrance compound vanillin has been developed starting from 4-cresol with the attention focused on improving the sustainability of all the reactions. The approach involves a three-step sequence of the quasi-quantitative selective clean oxybromination of 4-cresol, the high-yield selective aerobic oxidation of 2-bromo-4-cresol, and the quantitative methoxylation of 3-bromo-4-hydroxybenzaldehyde with the recovery of pure methanol. Herein, the pivotal oxidation and methoxylation reactions are logically investigated and developed into two concise methodologies. As a green alternative, the approach holds significant value for the sustainable manufacturing of vanillin.
Synthesis of Benzothieno[60]fullerenes through Fullerenyl Cation Intermediates
作者:Yutaka Matsuo、Yun Yu、Xiao-Yu Yang、Hiroshi Ueno、Hiroshi Okada、Hiromasa Shibuya、Yeong Suk Choi、Yong Wan Jin
DOI:10.1021/acs.joc.9b00549
日期:2019.5.17
Benzothieno[60]fullerenes were synthesized using fullerenyl cations as key intermediates. The reaction proceeded through a nucleophilic attack of the sulfur atom as a weak nucleophile to the fullerenyl cation electrophile. A monoarylated fullerene, (2-methylthiophenyl)hydro[60]fullerene, C60ArH (Ar = C6H4-SMe-2 and so on; four derivatives) was subjected to deprotonation with KOtBu to form a fullerenyl
苯并噻吩并[60]富勒烯是使用富勒烯阳离子作为关键中间体合成的。该反应通过作为弱亲核体的硫原子对富勒烯阳离子亲电体的亲核攻击而进行。将单芳基化的富勒烯,(2-甲基硫代苯基)氢[60]富勒烯,C 60 ArH(Ar = C 6 H 4 -SMe-2等;四种衍生物)用KO t Bu脱质子化以形成富勒烯基阴离子ArC 60 –,然后使用I 2氧化生成富勒烯阳离子ArC 60 +,通过富勒烯阳离子-S与产物的相互作用,导致分子内脱甲基环化。电化学和计算研究表明,由于稠合的噻吩基部分的HOMO相对较高,该化合物的带隙比通常的富勒烯衍生物略窄。