Regioselectivity Control in a Ruthenium-Catalyzed Cycloisomerization of Diyne-ols
作者:Barry M. Trost、Michael T. Rudd、Moisés Gulías Costa、Philip I. Lee、Andrew E. Pomerantz
DOI:10.1021/ol048351w
日期:2004.11.1
ruthenium-catalyzed cycloisomerization of diynes containing one silyl alkyne and one propargyl alcohol yields 2-silyl-[6H]-pyrans instead of the expected unsaturated acylsilanes except when additional conjugation of a aromatic ring is present at the delta-position. Under certain conditions, a facile ruthenium-catalyzed isomerization of the product takes place as well. This regioselectivity of the cyclization
含有一种甲硅烷基炔和一种炔丙醇的二炔的钌催化环异构化反应生成2-甲硅烷基-[6H]-吡喃,而不是预期的不饱和酰基硅烷,除非在δ位上存在芳环的其他共轭。在某些条件下,也容易进行钌催化的产物异构化。环化的这种区域选择性可以通过选择溶剂系统来控制。DFT计算证实了相对于酰基硅烷,预期的甲硅烷基吡喃稳定性更高。