多米诺钯催化双O-H键活化形成C-C和C-O键:合成6,6-二烷基-6 H-苯并[ c ]苯并二甲基苯
摘要:
提出了α,α-二烷基-(2-溴芳基)甲醇有效的钯催化多米诺反应为6,6-二烷基-6 H-苯并[ c ]色烯的反应。它们的形成可以通过一个五元的Pd(II)循环来解释,该循环有效地涉及与第二个分子的多米诺骨牌同质偶联,β碳裂解以及最后的分子内布赫瓦尔德-哈特维格环化。这种多米诺骨牌工艺实际上涉及打破五个σ键(2C–Br,2O–H和C–C)和形成两个新的σ键(CC和C–O)。这种机理途径是前所未有的,并进一步说明了过渡金属催化的作用。
Domino [Pd]-Catalysis: One-Pot Synthesis of Isobenzofuran-1(3<i>H</i>)-ones
作者:Lodi Mahendar、Gedu Satyanarayana
DOI:10.1021/acs.joc.6b01396
日期:2016.9.2
An efficient domino [Pd]-catalysis for the synthesis of isobenzofuran-1(3H)-ones is presented. The strategy shows broad substrate scope and is amenable to o-bromobenzyl tertiary/secondary/primary alcohols. Significantly, the method was applied to the synthesis of antiplatelet drug n-butyl phthalide and cytotoxic agonist 3a-[4′-methoxylbenzyl]-5,7-dimethoxyphthalide.
An efficient Pd-catalyzed domino reaction of α,α-dialkyl-(2-bromoaryl)methanols to 6,6-dialkyl-6H-benzo[c]chromenes is presented. Their formation can be explained via a five membered Pd(II)-cycle that efficiently involves a domino homocoupling with the second molecule, β-carbon cleavage, and finally intramolecular Buchwald–Hartwig cyclization. This domino process effectively involves breaking of five
提出了α,α-二烷基-(2-溴芳基)甲醇有效的钯催化多米诺反应为6,6-二烷基-6 H-苯并[ c ]色烯的反应。它们的形成可以通过一个五元的Pd(II)循环来解释,该循环有效地涉及与第二个分子的多米诺骨牌同质偶联,β碳裂解以及最后的分子内布赫瓦尔德-哈特维格环化。这种多米诺骨牌工艺实际上涉及打破五个σ键(2C–Br,2O–H和C–C)和形成两个新的σ键(CC和C–O)。这种机理途径是前所未有的,并进一步说明了过渡金属催化的作用。