Abstract
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.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
