Divergent Elementoboration: 1,3-Haloboration versus 1,1-Carboboration of Propargyl Esters

作者:Wilkins Lewis C; Soltani Yashar; Lawson James R; Slater Ben; Melen Rebecca L
来源:Chemistry - A European Journal, 2018, 24(29): 7364-7368.
DOI:10.1002/chem.201801493

摘要

This work showcases the 1,3-haloboration reaction of alkynes in which boron and chlorine add to propargyl systems in a proposed sequential oxazoliumborate formation with subsequent ring-opening and chloride migration. In addition, the functionalization of these propargyl esters with dimethyl groups in the propargylic position leads to stark differences in reactivity whereby a formal 1,1-carboboration prevails to give the 2,2-dichloro-3,4-dihydrodioxaborinine products as an intramolecular chelate. Density functional theory calculations are used to rationalize the distinct carboboration and haloboration pathways. Significantly, this method represents a metal-free route to highly functionalized compounds in a single step to give structurally complex products.

  • 出版日期2018-5-23