Diels–Alder Reactions of 9-Ferrocenyl- and 9,10-Diferrocenylanthracene: Steric Control of 9,10- versus 1,4-Cycloaddition
作者:Kirill Nikitin、Helge Müller-Bunz、Michael J. McGlinchey
DOI:10.1021/om400762f
日期:2013.10.28
Cycloadditions of benzynes, N-methyl- or N-phenylmaleimide, dimethyl acetylenedicarboxylate, and benzoquinone to 9-ferrocenylanthracene (1) and 9,10-diferrocenylanthracene (2) are described. Benzyne and 3-fluorobenzyne add to 1 and 2 to form the corresponding 9-ferrocenyl- or 9,10-diferrocenyltriptycenes; in contrast, bulkier benzynes such as 3-trifluoromethylbenzyne preferentially add to 2 across
描述了苯并炔,N-甲基或N-苯基马来酰亚胺,乙炔二甲酸二甲酯和苯醌与9-二茂铁基蒽(1)和9,10-二茂铁基蒽(2)的环加成。苯并和3-氟苯并zy加成1和2,形成相应的9-二茂铁基或9,10-二茂铁基三联烯;与此相反,笨重benzynes如3- trifluoromethylbenzyne优先添加到2 C两端1和C 4,形成6,11-茂铁-5,12-亚乙烯基-5,12- dihydrotetracenes。马来酰亚胺与1发生Diels–Alder反应,形成9-二茂铁基戊烯基10和11,但环2加成不仅发生在C 9和C 10上形成桶烯13,而且发生在C 1和C 4上分别产生内蒽和外加合物14和15的乙炔蒽。同样,DMAD与1形成11,12-二苯甲氧基-9-二茂铁基戊二烯(16),但通过在C 1和C 4上加成而与2反应形成17。水解16仅切割远离二茂铁基的酯。用碱和RX(R = Me,Et,CH