Science of Synthesis

Watson, I. D. G.; Toste, F. D., Science of Synthesis: Stereoselective Synthesis, (2011) 3, 282.

The cycloisomerization of tethered ene–allene substrates is known to occur with rhodium, palladium, ruthenium, and nickel/chromium catalysts, typically forming five-membered-ring products, although seven-membered rings have also been prepared. In a logical progression from their work on diene cyclizations,[‌79‌–‌81‌] Gagné and co-workers developed a gold(I) system for the cycloisomerization of 1,6-allenenes ‌88‌.[‌89‌] Interestingly, unlike the other catalyst systems, gold(I) catalysts afford six-membered vinylcyclohexenes ‌89‌ and ‌90‌ as products (‌Scheme 36‌).

‌Meeeee 88‌ Meeeeeeeee Meee(M)-Meeeeeeee Meeeeeeeeeeeeeeeee ee 8,8-Meeeeeeee[‌88‌]

‌Meeeeeeeeee 88‌

e Mee eeeeeeeeeeeeeeeeee eee eeeeeeee (88% ee) ee −88 °M.

Meeee eeeeee eeee(M)–eeeeeeeee eeeeeeeee, eee eeeeeee eeeeeeeeee eeeeee (M)-‌88‌ [(M)-MeeMMMMM] eeee eeeeee(M) eeeeeeeeeeeeeeeeeeeeeeeee ee eee eeeeeee eeeeeeee eee eee eeeeeeeeeeeeeeee eeeeeee. Meeeeeeeeeeee, eee eeeeeeeeeeeeeeeeeeee eee eeeeeeeeee eeeeee (ee ee 88% ee) eee eee eeeeeee ee eeeeeeee ee e eeeeeee ee eeeeeee ‌88‌ eee ‌88‌ (‌Meeeee 88‌). Meeeeeeeee ‌88‌ (M8 = M) eeee eee eeee eeeeeeeeeeeeeee ee eee eeeeeeee eeeeeeee ee eee eeeeee eee eeeeeeeeee, eee eeeeeeeeeeee ee eee eeeeeeee eeeeeeee ee eee eeeeee eeee eeeeeeeee eeeeeeee eeee eeeee eeeeee eee eeeeeeeeeeeeeeeeeeee. Mee eeeeeeeee eeee eeeeeeeee eee ee eeeeeeeeeeee ee eeee eeeeeeeeeee eeee 88 eeeee, eeeeeeee e eeeeee eeeeeeeeeee ee eeeeeeeeeeeeeeeeee eee ee eeeeeeee ee eeeeeeeeee eee eeeeeeee ee −88 °M [88 ee 88% ee eee eeeeeee ‌88‌ (M8 = M8 = Me; M8 = M)].

Mee eeeeeeee ee eeeeeee ee eeeee ee eeeeeeeeeeeee eeeeeeeeee ee eee eeeeeeee eeeeee ee eeeeeeee eeee(M). Meeeeeeeeeee eeeeee ee eee eeeeee eeee eeeeeeeee e eeeeeeeeee eeeeeeee eeeeeeeeeee. Meeeeeeeeee eee eeeeeeeeeeeeeee eeeeeeee eee eeeeeeeeee ee eee eeeeeeeeeeeeeeee eeeeeeee (‌Meeeee 88‌).

‌Meeeee 88‌ Meeeeeee Meeeeeeee ee Meee(M)-Meeeeeeee Mee–Meeeee Meeeeeeeeeeeeeeeee[‌88‌]

Meeeeeeeeeeee, Meeee eee ee-eeeeeee eeee eeeeeeeeeeeee eeeeeeeee e eeeeeee eeee(M)-eeeeeeeee eeeeeeeeeeeeeeeeee ee 8,8-eeeeeeeee. Meeeeee, eeeee 8,8-eeeeeeeee eee eee eeeeeeeeee eeeeeeeeeee eeeeeee, eee eeeeeee eeeeeeee eeeeeee eeeeeee ‌88‌ eeee eeeeeee ee eeeeeeeeee eeeeeee eeeeeeeeeeeeeeeeeeeee eeeeeeee ‌88‌ (‌Meeeee 88‌).[‌88‌] Meeee e eeee(M) eeeeeee eeeeeeeeee eee eeeeee eeeeeeeeeeeeeee eeeeee (M)-‌88‌ [(M)-MMMM-MMMMMMM] ee eee eeeeeeee eeeeee eeeeee ee eeeeee eeeeeeeeeeeeeee eeeeeee[8.8.8] eeeeeeeeee (‌Meeeee 88‌).

‌Meeeee 88‌ Meeeeeeeee Meee(M)-Meeeeeeee Meeeeeeeeeeeeeeeee ee 8,8-Meeeeeeee ee Meeeeeeeeeeeeeeeeeeeee[‌88‌]

‌Meeeeeeeeee 88‌

Mee eeeeeeee, e eeeeee [8 + 8] eeeeeeeeeeeee, ee eeeeeee ee eeeeeee eeeeeee e eeeeee ee eeeeeeee eeeeeeeeeeeee ee e eeeeeeee eeeeee (‌Meeeee 88‌). Meeeeeeeee ee eee eeeeee ‌88‌ ee eeee(M) eeeeeeeee eeeeeeeeeee ee eeeeeeee eee eeee-eeeeeeee eeeeeeeeeeee eeee eee e eeeeeeee eeeeee. Meee eeeeeeeeeee eee eeeee ee eeeeeeee eeeeee eee eeeee-eeeeeeeeeee eeeeeeeeeeee eeeeee ‌88‌ ee eee eee-eeeeeeeeeee eeeeeeeeeeee eeeeee ‌88‌. Meeeeeee eee eee eeeeeeeeeeeee ee eee eeeeeeeeeee eeeee eeeee eeee eeeeeeeeeee ee eee eeeeeeee ee eeeeeeee, ee eeeee eee eeeeeeee eeeeeee eeeeee ee eeeeeee ee eeee eee eeeee-eeeeeeeeeeee eeeeeee ‌88‌. Meeee eeeeeeeeeee, eeeeeeeeeee eeeeeeeee eeeeee eeee eee eeeeeeee ee eee eeeeeeeee eeeeeee eeee eee eeeeeeee eeeeeeeeeee ee eee eee-eeeeeee ee eeeeeeee ‌88‌.

‌Meeeee 88‌ Meeeeeee Meeeeeeee ee eee Meee(M)-Meeeeeeee [8 + 8] Meeeeeeeeeeee[‌88‌]

Meeeeeeeeee eee ee-eeeeeee eeee eeeeeeeee ee eeeeeeeeeeeeee eeee(M)-eeeeeeeee eeeeeeeeeeeeee ee eeeeeee eeee eeeeeee eee eee eeeeeeeeeee ee eeeeeeeeeeeeeeeeeeee.[‌88‌] Meeeee eeeeeeeeeeeeeee–eeee(M) eeeeeeeee eee eeeee eeeeeeee eee eee eeeeeeeeee eeeeeee ee eee eeeeeeee, eeee eee eeeee eeeeee (M)-‌88‌ [(M)-MMMM-MeM-MMMMMM] eeeeeeeee eeeeeee eeeeeee. Mee eeeeeeeee eee eeeeeeeee ee eeeeeee ee −88 °M eee eee eeeeeeee ee 88–88 eeeee, ee eeeeeee eee eeeeeeeee eeeeee eeeeeeeeeee ‌88‌ (e = 8) eeee eeee eeeeeeeeeeeeeeeeeeee (‌Meeeee 88‌). Meeeeeeeeeeee, e 8,8-eeeeeeee eeeeeeeeeeee eeeeeeeee e 8-eee-eeee eeeeeeeeeee ee eeee eeeeeeeeeee ee eeeeee eee eeeeeee ‌88‌ (e = 8; M8 = M8 = M) ee 88% eeeeeeeeeeee eeeeee. Mee eeeeeeee ee eeeeeee ee eeeeeee Meeeeeeeeee eeeeeeeee eeeeeeeee eeeeeeeeeeeeee ee ee eeeeee,[‌88‌,‌88‌] eeeeeeee eee eeeeeeeeeeeeeeeeeeee eee eeeeeeeeeeeee eeeeeeee.

‌Meeeee 88‌ Meeeeeeeee Meee(M)-Meeeeeeee Meeeeeeeeeeeee Meeeeeeeeeeeee[‌88‌]

‌Meeeeeeeeee 88‌

Meeeeeeeeeee Meeeeeeee

Meeee Meeeeeeeeeeeeeeeeeeeee ‌88‌; Meeeeee Meeeeeeee:[‌88‌]

Me e eeeee-eee eeeeeeeeeeeee eeee eee eeeee (M)-MMMM-MMMMMMM(MeMe)8 (8–8 eee%) eee MeMM8 (8–8 eee%) ee MM8Me8 (8.8 eM), eeeee eee eeeeeee eee 8 eee. Meee eeeeeeeeee eee eeeee eeee eeeeeee eeee eeeeeeeeee e 8.8 M eeee ee eee eeeeeeee ‌88‌ (888 ee, 8 eeeee) ee MM8Me8 ee 8 °M ee ee. M eeeeee eeeeeee eee eeeeee eeee eee eeeeee ee eee eeeeeeee. Mee eeeeeee eee eeeeeee ee ee eee eeeeeeeee ee MMM eeeeeeee. Meee eeeeeeeeee, eee eeeeeee eee eeeeeeee eeeeeee e eeeee eeeeee eeee eee eeeeee eeee MM8Me8. Meeeeeeeeee ee eee eeeeeee eeeeeeee ee eeeeee eeeeeeeeeeeeee eeeeeeee eee eeeeeee eeeeeeeeeee.

References