Bicyclo[4.2.0]octa-1,3,5-triene: 2-Mono- and 2,5-Disubstituted Derivatives<i>via</i>Highly Regioselective Lithiation of Its Cr(CO)<sub>3</sub>Complex and<i>via</i>Reductive Silylation/Oxidation
作者:E. Peter Kündig、Celia Ferret、Bruno Rudolph
DOI:10.1002/hlca.19900730720
日期:1990.10.31
0]octa-1,3,5-triene)]tri-carbonylchromium complexes (e.g. 13 (R′R″Me3Si) and 14 (R′Me3Si, R″CHO)) as single products. The Cr(CO)3 group can be easily removed by oxidation (I2, Ce(IV), O2/light; 2 examples each) to give the free arenes. Base-catalyzed (CsF, DMF/D2O) deuterodesilylation of 13 yields the [(2,5-2H2)bicyclo[4.2.0]octa-1,3,5-triene]chromium complex 15, and treatment of 2,5-bis(trimethylsilyl)
的治疗[η 6 - (二环[4.2.0]辛三烯1,3-5)] tricarbonylchromium(0)(2)用BuLi或锂2,2,6,6- tetramethylpiperidinide(TMPLi)产生了一个在C(2)的高度区域选择性去质子化。与亲电(6个实施例)随后的反应可以得到:η 6 - (2-R -双环[4.2.0]辛-1,3,5-三烯)] tricarbonylchromiurn络合物3和5 - 9在中度(RI,50%; RCHO,67%)至良(RMe,D,SiMe 3,CO 2 Me,> 80%)产率(方案1)。与三羰基类似反应(η 6 -茚满)铬(10)配合在C(4)和C(5)取代的的给定的混合物(方案2)。在10中,强烈的碱基TMPLi强烈支持去环连接的去质子β。双锂化/电子试剂添加到2授予访问[η 6 - (2-R'-5-R“ -双环[4.2.0]辛-1,3,5-三