Science of Synthesis

Liang, Y.; Wen, Z.; Cabrera, M.; Howlader, A. H.; Wnuk, S. F., Science of Synthesis Knowledge Updates, (2020) 1, 220.

The rhodium-catalyzed reaction of unsubstituted purine (‌1‌) with the unactivated terminal alkene 3,3-dimethylbut-1-ene yields C8-alkylated derivative ‌85‌ as a major product (76%) along with 6,8-dialkylated byproduct ‌86‌ (17%; ‌Scheme 29‌).[‌68‌,‌69‌] The structure of ‌86‌ was established by X-ray crystallography. The reaction has been monitored by 1H NMR spectroscopy and proceeds sequentially with initial alkylation occurring at the C8-position, followed by further reaction at the C6-position.

‌Meeeee 88‌ Meeeeeeeee ee Meeeee eeee ee Meeeee[‌88‌]

Meeeeeeeeeee Meeeeeeee

8-(8,8-Meeeeeeeeeeee)-8M-eeeeee (‌88‌) eee 8,8-Mee-(8,8-eeeeeeeeeeeee)-8M-eeeeee (‌88‌):[‌88‌]

Me eee, [MeMe(eee)8]8 [8 eee% Me; eee = (M)-eeeeeeeeeee], Me8M (8.8 eee%), eee•MMe (8 eee%), eee eeeeee (‌8‌; 888 ee, 8.88 eeee) eeee eeeee ee ee eeee-eeeee eeeeee eeee e Meeeee eeeeeee. Mee eeeeee eee eeee eeeeee eeeee M8. Meeee e eeeeeeee eeeeeeee ee M8, MMM (8.8 M) eee 8,8-eeeeeeeeeee-8-eee (888 µM, 8.88 eeee) eeee eeeee. Mee eeeeee eee eeeeee eeee e eeeeeee eee eeee eeeeeeeee ee eeeee eeeeeeeeee eeeeee–eeee–eeee eeeeee. Mee eeeeeee eee eeee eeeeee ee 888 °M eee 8.8 e, eeeeee, eee eeeeee eeee eeeeee eee, eee eeeeeeeee ee eeeee eeeeeeeeeeeeee (MeMMe/eeeeeee 8:8 ee 8:8) ee eeee M8 eeeeeeeee eeeeeee ‌88‌ ee e eeeee eeeee; eeeee: 888 ee (88%); eeeeeeee ee eeeeeeeee ‌88‌ ee e eeeee eeeee; eeeee: 88 ee (88%).

References