1239694-97-3Relevant academic research and scientific papers
1,3-steric induction in intermolecular radical reactions mediated by a Co2(CO)6-metal core
Melikyan, Gagik G.,Spencer, Ryan,Rowe, Aaron
, p. 3556 - 3562 (2010)
Diastereoselectivity of propargyl coupling reactions can be controlled by using the bulkiness of a γ-substituent as a stereochemical tool. This 1,3-steric induction was observed with γ-t-Bu and γ-Me3Si groups, both favoring a d,l-configuration of the head-to-head coupling products, 3,4-disubstituted 1,5-alkadiynes (d,l-95-100%). X-ray crystallography analysis suggests that the most favorable orientation of converging propargyl radicals is the one in which the bulky γ-substituents are positioned anti to each other. Overall, the synthetic strategy of employing a Me3Si auxiliary group involves five steps and affords, with 28-33% overall yields, pure d,l-3,4-diaryl-1,5-hexadiynes, otherwise hardly accessible.
