Complete details of an asymmetric synthesis of apicularen (1) are described. The synthesis has been accomplished using a highly diastereo- and enantioselective [4 + 2] annulation for the assembly of the functionalized pyran core. An underdeveloped lactonization method involving an NaH promoted transesterification of an advanced intermediate bearing an aryl cyanomethyl ester was used for the macrolactonization step.
Divergent Synthesis of Functionalized Carbocycles through Organosilane-Directed Asymmetric Alkyne–Alkene Reductive Coupling and Annulation Sequence
作者:Jie Wu、Yi Pu、James S. Panek
DOI:10.1021/ja3083945
日期:2012.11.7
organosilane-directed alkyne-alkene reductive coupling of readily available propargylsilanes is used to access densely functionalized chiral allylsilanes. The divergent reactivity of the allylsilanes can be controlled to afford a range of novel carbocyclic ring systems through an intramolecular allylation, [3+2] annulation, and Sakurai-like homodimerization.
Total Synthesis of (+)-Isatisine A: Application of a Silicon-Directed Mukaiyama-Type [3 + 2]-Annulation
作者:Jihoon Lee、James S. Panek
DOI:10.1021/acs.joc.5b00051
日期:2015.3.20
synthesis highlights the use of a highly diastereoselective Mukaiyama-type [3 + 2]-annulation of allylsilane 5 with the unsaturated aldehyde 9a to assemble the functionalized tetrahydrofuran core of isatisine A. A convergentroute to the framework of the natural product was established that employed a substrate-controlled indole coupling that was followed by a late-stage intramolecular copper(I)-mediated
Complete details of an asymmetric synthesis of apicularen (1) are described. The synthesis has been accomplished using a highly diastereo- and enantioselective [4 + 2] annulation for the assembly of the functionalized pyran core. An underdeveloped lactonization method involving an NaH promoted transesterification of an advanced intermediate bearing an aryl cyanomethyl ester was used for the macrolactonization step.
Total Synthesis of (+)-Isatisine A
作者:Jihoon Lee、James S. Panek
DOI:10.1021/ol102848w
日期:2011.2.4
Totalsynthesis of (+)-isatisine A is described based on the application of a silyl-directed Mukaiyama-type [3 + 2]-annulation for the preparation of a fully substituted furan core. The indole branch forming the quaternary carbon center at C2 was constructed by addition to an intermediate N-acyliminium ion derived from aminal 4. In addition, the fused tetracyclic framework including furan core was