Simple Protocol for Synthesis and Cleavage of Tetrahydropyranyl Ethers Using FeSO<sub>4</sub>as an Inexpensive Catalyst
作者:Babasaheb P. Bandgar、Suhas P. Kasture
DOI:10.1002/jccs.200100127
日期:2001.10
Protection and deprotection of alcohols and phenols as tetrahydropyranyl ethers (THP ethers) using anhydrous FeSO 4 under microwave irradiation without solvent is carried out.
Concise, Enantioselective, and Versatile Synthesis of (−)-Englerin A Based on a Platinum-Catalyzed [4C+3C] Cycloaddition of Allenedienes
作者:Ronald Nelson、Moisés Gulías、José L. Mascareñas、Fernando López
DOI:10.1002/anie.201607348
日期:2016.11.7
A practical synthesis of (−)‐englerin A was accomplished in 17 steps and 11 % global yield from commercially available achiral precursors. The key step consists of a platinum‐catalyzed [4C+3C] allenediene cycloaddition that directly delivers the trans‐fused guaiane skeleton with complete diastereoselectivity. The high enantioselectivity (99 % ee) stems from an asymmetric ruthenium‐catalyzed transfer
Efficient synthesis of carbazoles via PtCl2-catalyzed RT cyclization of 1-(indol-2-yl)-2,3-allenols: scope and mechanism
作者:Wangqing Kong、Chunling Fu、Shengming Ma
DOI:10.1039/c1ob06474f
日期:——
A detailed study on the scope of the efficient PtCl2-catalyzed synthesis of carbazoles from 1-(indol-2-yl)-2,3-allenols is described. Through isotopic labeling experiments, it is confirmed that the reaction proceeds through a unique metal carbene intermediate, which undergoes subsequent highly selective 1,2-hydrogen migration to afford carbazoles. The reaction shows wide scope and allows the introduction of a variety of different substituents at different positions on the carbazole due to the substituent-loading capability of both indole and the allene moiety.