作者:David Sperandio、Hans-J�rgen Hansen
DOI:10.1002/hlca.19950780321
日期:1995.5.10
Benz[a]azulene (1) is synthesized in five steps (cf. Scheme 2) starting from commercially available 2-iodobenzyl alcohol (4) and tropylium tetrafluoroborate in an overall yield of 44%. The key step (cf. also Scheme 1) is the intramolecular Heck reaction of the 8-phenylsulfonyl-substituted heptafulvene 7, which leads in nearly quantitative yield directly to 10-(phenylsulfonyl)benz[a]azulene (8). The
从市售的2-碘苄醇(4)和四氟硼酸对苯二酚开始,以五个步骤(参见方案2)合成苯并[ a ] azulene(1),总收率为44%。关键步骤(另请参见流程1)是8-苯基磺酰基取代的七氟醚7的分子内Heck反应,该反应几乎定量地直接产生10-(苯基磺酰基)苯并[ a ] az [ 8 ]。8的磺酰化可以通过朱莉娅法(Na 2 S 2 O)来完成。DMF / H 2 O中在85–90°下为4 / NaHCO 3,因此收率为78%的纯1。在-78°下,THF中的PhLi或PhCul导致8的苯基化在C(9)上发生区域选择性。在室温下用邻氯苯甲腈在甲苯中对形成的二氢azulenes进行脱氢反应,以70%的收率得到9-苯基-10-(苯基磺酰基)-苯并[ a ] azulene(9)(参见方案3),同样可以在DMF / H 2 O中用Na 2 S 2 O 4 / NaHCO 3脱磺酰化,收率良好。将PhL