Functionalized Chromans and Isochromans via a Diastereoselective Pd(0)-Catalyzed Carboiodination
摘要:
A diastereoselective approach to isochromans and chromans via Pd(0)-catalyzed carboiodination is reported. The transformations using this methodology display excellent yields and diastereoselectivities as well as broad functional group compatibility. The selectivity observed in these cyclizations, forming isochroman or chroman targets, is postulated to originate from the minimization of A(1,2) strain and axial axial interactions, respectively. This method has also been used to highlight the concept of reversible oxidative addition to carbon iodine bonds in polyiodinated substrates.
Functionalized Chromans and Isochromans via a Diastereoselective Pd(0)-Catalyzed Carboiodination
摘要:
A diastereoselective approach to isochromans and chromans via Pd(0)-catalyzed carboiodination is reported. The transformations using this methodology display excellent yields and diastereoselectivities as well as broad functional group compatibility. The selectivity observed in these cyclizations, forming isochroman or chroman targets, is postulated to originate from the minimization of A(1,2) strain and axial axial interactions, respectively. This method has also been used to highlight the concept of reversible oxidative addition to carbon iodine bonds in polyiodinated substrates.
Palladium-Catalyzed Disilylation and Digermanylation of Alkene Tethered Aryl Halides: Direct Access to Versatile Silylated and Germanylated Heterocycles
作者:Marco Wollenburg、Jonathan Bajohr、Austin D. Marchese、Andrew Whyte、Frank Glorius、Mark Lautens
DOI:10.1021/acs.orglett.0c01169
日期:2020.5.1
A method for the palladium-catalyzed disilylation and digermanylation of aryl halides bearing a tethered alkene has been developed. The mechanism is thought to proceed via Heck-type cyclization, followed by C-H activation, resulting in a reactive fused-palladacycle. A wide variety of disilylated and digermanylated heterocycles are obtained from readily available aryl halides in high yields with various