Science of Synthesis

Watson, I. D. G.; Toste, F. D., Science of Synthesis: Stereoselective Synthesis, (2011) 3, 257.

The rhodium-catalyzed reactions result in some of the most reliable and wide-ranging substrate scopes of all currently developed asymmetric cycloisomerization reactions. These reactions are highly efficient and provide excellent enantioselectivities, often using 2,2′-bis(diphenylphosphino)-1,1′-binaphthyl (BINAP) as the chiral ligand. The first racemic rhodium-catalyzed cycloisomerization reaction was developed by Zhang and co-workers.[‌44‌] 1,6-Enyne substrates ‌32‌ containing Z-alkenes react with cationic rhodium(I) complexes in 1,2-dichloroethane (0.1 M) at room temperature, to afford 1,4-diene products ‌33‌ in excellent yield (‌Table 3‌, entries 1–3). Interestingly, although the Z-alkenes cycloisomerize efficiently, the E-alkenes are often unreactive. Additionally, it is essential to prepare the clean catalyst precursors before generating the cationic complexes in situ by reacting with silver(I) hexafluoroantimonate. Dimeric rhodium catalysts containing ligand ‌34‌ or 1,4-bis(diphenylphosphino)butane {[RhCl(BICPO)]2 and [RhCl(dppb)]2} are both excellent precatalysts for the reaction. Additionally, a cyclic alkene affords the cis-fused ring system (entry 3), while the but-2-enyl but-2-ynoate furnishes an α-methylene lactone (entry 4).

‌Meeee 8‌ Meeeeee(M)-Meeeeeeee Meeeeeeeeeeeeeeeee ee 8,8-Meeeee[‌88‌]

Meeee	Meeeeeeee	Meeeee	Meeeeeee (eee%)	Meeeeee	Meeee (%)	Mee
8			88		88	[‌88‌]
8			8		88	[‌88‌]
8		eeee	88		88	[‌88‌]
8		eeee	88		88	[‌88‌]

Mee eeeeeeee eeeeeeeee eee eeeeeee(M)-eeeeeeeee eeeeeeeeeeeeeeeeee eeeeeeee ee eeeeeee eeeeeeeee eeeeeeeeeeee ee eee eeeeeee(M) eeeeeee ee eee eeeee. Meeeeeeee eeeeeeeeeee eeee eeeee eee eeeeeee(MMM) eeeeeeeeeeeeeeeeeee, eeeeeeee ee eeeeeeeeeeeee β-eeeeeee eeeeeeeeeee ee eeee eee M-eeeeee eeeeeeee. Meeeeee, eeeeeeeee eeeeeeeeeee eeeeeeee eee 8,8-eeeee eeeeeee (‌Meeeee 88‌).

‌Meeeee 88‌ Meeeeeee Meeeeeeee ee Meeeeee(M)-Meeeeeeee Meeeeeeeeeeeeeeeee

Meeee eee ee-eeeeeee eeee eeeeeeee eee eeeee eeeeeeeeee eeeeeee-eeeeeeeee eeeeeeeeeeeeeeeeee ee 8,8-eeeeee ‌88‌ (‌Meeee 8‌).[‌88‌] M eeeeee ee eeeeee eeeeeeeee eeeeeeeeee eee eeeeeeeeeeee eeee eeeeeeee, eeee ‌88‌ (MMMMM), ‌88‌ (Me-MeMeee), eee ‌88‌ (MMMM) eeeeeeeee eee eeeeeee eeeeeeeeeeeeeeeeeeee. Meeeeeeeeeeee, eee eeeeeeeee eeeeeeeee 8,8′-eee(eeeeeeeeeeeeeeeee)-8,8′-eeeeeeeeee (‌88‌, MMMMM) ee eeeeeeeeee eeeeeeeeee ee eeee eeeeeeee. Meee eeeee eeeeeeeeee eeee eeeeeeee eee eeee eeeeeeeeeeeeeeeeeeee eee eeeeee eeee eeeeeeee (‌Meeee 8‌, eeeeeee 8–8). Meeeee eeeeee eee eee eeeeeee, eeee eeeeee eeeeeee ee eee eeeeeeeee eeeeeeeeeeee eeeeeeeee eeee eee eeeee eee eeeeeeeeeeeeeeeeee ee eee eeeeeee ‌88‌. Mee 8,8-eeeee eeeeeee eeeeeee eeeeeeeeee ee eee 8,8-eeeee ee eee eeeeeeee ee eee eeeeeee(M) eeeeeeee; eeee eeeeeeee eeeeeeeeeeeeee eee eeeeeeeee ee eeeeeeeee eeeeeeeeee eee eeeeeeee, eee eeeeeeeee ee ee eeee ee eee eeeeeeeeee eeee eeeeeeee. Meeeeeeeeeeee, eee ee eeee eeeeeeeeeee ee eee eeeeeee eeeeeeee eeeee ee e eeeeeeeeeee eeeeeeeeeee ee eeee eee eeeee eee eeeeeeeeeeeeeeeeee.[‌88‌,‌88‌] Me eeeeeeeeee, (M)-MMMMM [(M)-‌88‌] eeeeeee eeeeeeeee eeee eeeeeeeeeeeeeeeeeeee eee eeeeee eeee e eeee eeeeeee ee eeeee eeeeeeeeee (eeeeeee 8–8).

‌Meeee 8‌ Meeeeeeeee Meeeeee(M)-Meeeeeeee Meeeeeeeeeeeeeeeee ee 8,8-Meeeee[‌88‌–‌88‌]

e Mee eeeeeeee eee eeeeeeee ee eeee eeee [MeMe(eee)]8 eee (M)-MMMMM.

Meeee eee ee-eeeeeee eeee eeeeeee eeeee eeeeeeeeeee ee eee eeeeeeeeee eeeeeeeee ee α-eeeeeeeee eeeeeeee ‌88‌ (M = M).[‌88‌] Meeee eeeeeeeee eeee eeeeeee eee ee eee eeeeeeee ee e eeeeeee eeeeeee eeeeeee {[MeMe(eee)]8}, eeeeee (M)-‌88‌ [(M)-MMMMM], eee eeeeee(M) eeeeeeeeeeeeeeeeeeee ee 8,8-eeeeeeeeeeeeee ee eeee eeeeeeeeeee ee eeeeee eee eeeeeee eeeeeee ee eeeeeee eeee eeeeeeeee eeee eeeee eee eeeeeeeeeeeeeeeeee (‌Meeeee 88‌). Mee eeee eeeeeeee eee eeee eeee eeeeeee ee eeeee eeeeee ee eeeeeee eeeeeeeeeeeeee eeeeeee ee eeee eeeeee eee eeeeeeeeeeeeeeeeeeee.[‌88‌] Mee eeeeeeee ee eeeee eeeeeee eeeeeeeeee ee e eeee eeeee ee eeeeeeeeee, eeeeeeeee eee eeeeee eeeeeeee ‌88‌ (M = MMe) ee eeee eeeee eee eeeeeeeeeeeeeeeeee (‌Meeeee 88‌). Meeeeeeeeee eeeeee ‌88‌ (M = MM) ee eee eeeeeee eee eeeeeeeeeee, eeeeeeeeee eeeeeee eeeee eeeeee eeeee eeeeeeeeeeeee ee eee eeeee-eeeeee.

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

‌Meeeeeeeeee 88‌

Mee eeeeeeeee eeeee ee eee eeeeeeeeee eeeeeee-eeeeeeeee eeeeeeeeeeeeeeeeee eee eeeeeeeeeeee eeee e eeeeee eeeeeeeee ee (+)-eeeeeeeeeee (‌Meeeee 88‌).[‌88‌] Me eeeeeeee, ee eee eeeeeeeeeee eeee eeee 8,8-eeeee eeeeeeeeee, eeee eeeeeeeeeeee ee eee eeeeeee eeeeeeee, eeeeeeeeeee ee e eeeeeeeeeeeeeee eeeeeee eeeeeeeeee ee eeeeee eee eeeeeeeeeee eeeee eeeeeeee eeee eeee eeeeeeeeeeeeeeeeee.[‌88‌]

‌Meeeee 88‌ Meeeeeeee ee (+)-Meeeeeeeeee eee Meeeeeeeee Meeeeee(M)-Meeeeeeee Meeeeeeeeeeeeeeeee[‌88‌]

Meeeeeee eee ee-eeeeeee eeee eeeeeeee eee eeeeeee(M)-eeeeeeeee eeeeeeeeee eeeee eeeeeeeeeee eeeeeeee ee eeeeeeeeee eeee eeeeeeee eeeeeee.[‌88‌–‌88‌] M eeeeeeee eeeeeee eee eee eeeeeee ee eeee eeeeeee ee ee eeeeee eee eeeeeeeee eeeeeeeee eeeeeee ([Me{(M)-MMMMM}]MeM8) eeeeee eeee eee eee eeee eeeeeeeeeeee ee eeee eeeeeeee. Mee eeeeeeee ee eeeeeee eee e eeeeeee ee M-eeeeeee eeeeeeee ‌88‌ ee eeeeee eee eeeeeeeee ‌88‌ ee eeeeeeeee eeeeee eee eeeeeeeeeeeeeeeeeeee (‌Meeee 8‌).

‌Meeee 8‌ Meeeeee(M)-Meeeeeeee Meeeeeeeeeeeeeeeee ee Meeeeeee Meeeee 8,8-Meeeee[‌88‌–‌88‌]

Meeeeeeee	Meeeeee	ee (%)	Meeee (%)	Mee
		>88	88	[‌88‌]
		88	88	[‌88‌]
		88	88	[‌88‌]
		>88	88	[‌88‌]

Mee eeeeeee eee eee eeeeeeeee ee eee eeeeeeee eeeee eeeee eeee eee eee ee e eee eeee ee eee eeeeee eeeeeeeeee eeeeeeeee ee (−)-eeeeeeeeeeeee. Mee eee eeeeeeeeeeee ‌88‌ ee eeeeeeeee eeee eee eeeee eeeeeee eeeeeeee ‌88‌ ee 88% eeeee eee eeee eeeeeee eeee 88% eeeeeeeeeeee eeeeee (‌Meeeee 88‌). Mee eeeeeeeee eeeeeeee eeeeeee ([Me{(M)-MMMMM}]MeM8) ee eeeee eeeeeee eee eeee eeeeeee ee eeeee eeeeeee. Mee eeeeeeee ‌88‌ eeeeeeeeee ee eeeeeeeeeeee eeee eee eeeeeeeʼ eeeeeeee eeeeeeeee eee eeeeeeeee eeeeeeeeeee e eeeeee eeeeeeeeee eeeee eeeeeeeee ee (−)-eeeeeeeeeeeee.

‌Meeeee 88‌ Meeeeeeee ee (−)-Meeeeeeeeeeee eee Meeeeeeeee Meeeeee(M)-Meeeeeeee Meeeeeeeeeeeeeeeee[‌88‌–‌88‌]

Meeeeee eee ee-eeeeeee eeee eeeeeeeee ee eeeeeeeeee eeeeeeeeeeeeeeeeee eeeeeeee ee 8,8-eeeeee ‌88‌ ee eeeeee 8-eee- eee 8-eeeeeeeeee[8.8.8]eeee-8-eee eeeeeeeeeee ‌88‌ (M = MMe, M), eeee eeee eeeeeeeeeeeeeeeeee (‌Meeeee 88‌).[‌88‌] Mee eeeeeeeee eeeeeeee eeeeeee ee e eeeeeee–eeeeee eeeee eeeeeee eeee ee eeeeeee eeeeeeeeeeeee ee eee eeeeee eeeeee. Meeeee eeeee ‌88‌ ee eeeeeee eee eeeeeeee e eeee eeeeeeee, eeee eeeeeeee-eeeeeeee eeeeeeeeeee eeee e eeeeeeee eeeeeeeeeeee eeeeee. Me eeee, eee eee ee eeeeeeeee eeeeeeeeee (eeee ee eeee ee MMMMM) eeeee eeeee eeeeeeeeee eeee eee eeeeee eee ee eee eeeeeee[8.8.8]eeeeeee eeeeeeee. Meeee ‌88‌ eeeeeeee eee eeeeeeeeeeee eeeeeeee eeee eeee ee eeeeeeeee eeeeeeeeeeeeeeeeeeee (‌Meeeee 88‌).

‌Meeeee 88‌ Meeeeeeeee Meeeeee(M)-Meeeeeeee Meeeeeeeeeeeee/Meeeeeeeeee ee 8,8-Meeeee[‌88‌]

‌Meeeeeeeeee 88‌

Meeeeeeeeee eee ee-eeeeeee eeee eeeeeeeee ee eeeeeeeeee eeeeeee(M)-eeeeeeeee eeeeeeeeeeeeeeeeee–eeeeeeeeeeeee eeeeeeee (‌Meeeee 88‌).[‌88‌] Meeeeeee eee eeeeeee–8,8′-eee(eeeeeeeeeeeeeeeee)-8,8′-eeeeeeeeee eeeeeee ee eee ee eeeeeeeee eeeeeeee eee eeee eeeeeeeeeeeeee, eee eeeeeee eeeeeee eeeeeee eeeee eee eeeeeeeeee eeeeee ‌88‌ (MMMMMMM) ee eeeeee eeeeeeeee. Meeeeeeee ee e eeeeee ee eeeeeeeeeeeeee 8,8-eeeeee ‌88‌ eeee eeeeee eeeeeeeeeeeeee eee eee eeeeeeee ee eeeeeeeeeeeeee ee 88 °M, eeeeeeeee eee eeeeeeeeeeeeee eeeeeeeee eeeeeeeeeeeeeeeeeeeeeee ‌88‌ eeee eeee eeeeeeeeeeeeeeeeeeee (‌Meeeee 88‌).

‌Meeeee 88‌ Meeeeeeeee Meeeeee(M)-Meeeeeeee Meeeeeeeeeeeeeeeee–Meeeeeeeeeeeeee ee 8,8-Meeeee[‌88‌]

‌Meeeeeeeeee 88‌

Meeeeee eee ee-eeeeeee eeee eeeeeeeee e eeeeeee-eeeeeeeee eeeeeeeee eeeeeeeeeee eeeeeeee ee 8,8-eeeeee eeee ee eeeeeeee ee eeeeeeee.[‌88‌] Mee eeeeeeee ee eeeeeee ee eeeeeee ee eeeeeeeee ee e eeeeeee eeeeeee eeeeeeee ee eeeeeeee eeee eee 8,8-eeeee ee eeee e eeeeeee(MMM) eeeeeeeeeeee. Meeeeeeee eeeeeeeeeee eeee eeee eeeeeee eeeeeeeee eee eeeeee eeeeeeee. Mee eeeeeeee ee eeeeeeee eeeeeeeeee ee eee eeeeeeee ee eeeeee eeeeeeeee eeeeeeeee eeeeeee.[‌88‌] Me eee eeeeeeee ee eeeeeee (M)-‌88‌ [(M)-MMMMM] ee (M)-‌88‌ [(M)-Me-MeM-MMMMMM], 8,8-eeeeee ‌88‌ eeeeee eeeeee eeeeeeee ‌88‌ eeee eeee eeee eeeeeeeeeeee eeeeee (‌Meeee 8‌). Mee eeeeeeee eeeee ee e eeee eeeeeeeee eeeee eeeeeeeee eeeeee eeee eeeeeeee, eeeeee, eee eeeeee eeeeeee. Meeeeeee (M)-‌88‌ [(M)-MMMMMMMMM] eeeeeee eeeeeee eeeeeee eeeeeeee ee eeeeeeeeeeee eeeeeeeeeeee eeeeeeee, eeee eee eeeeeeeeeee eeeeee eee eeeeee (‌Meeee 8‌, eeeeeee 8 eee 8) ee eeeeeee eee eeeeeeee eeeeee eeeeeeeeeee ee eeee eeeeee eee eeeeeeeeeeeeeeeeeeee.

‌Meeee 8‌ Meeeeeeeee Meeeeeeee Meeeeeeeeee ee 8,8-Meeeee[‌88‌–‌88‌]

Meeee	Meeeeeeee	Meeeee	Meeeeee	ee (%)	Meeee (%)	Mee
8		(M)-‌88‌		88	88	[‌88‌]
8		(M)-‌88‌		88	88	[‌88‌]
8		(M)-‌88‌		88	88	[‌88‌]
8		(M)-‌88‌		88	88	[‌88‌]
8		(M)-‌88‌		88	88	[‌88‌]
8		(M)-‌88‌		88	88	[‌88‌]
8		(M)-‌88‌		88	88	[‌88‌]

Meeeeeeeeeee Meeeeeeee

8,8-Meeeee ‌88‌; Meeeeee Meeeeeeee:[‌88‌]

Me e eeeeeeee, e Meeeeee eeee eee eeeeeee eeee eeeee ‌88‌ (8.8 eeee), [MeMe(eeee)]8 (88 eee%), eee 8,8-eeeeeeeeeeeeee (8 eM). Mee eeeeeee eee eeeeeee eee 8 eee, eeeeeeee ee eeeeeeee ee MeMeM8 (88 eee%). M eeeeeeeeeee eee eeeeeeee eee eee eeeeeee eee eeeeeee ee eeee ee ee eeeee MMM eeeeeeeee eeee eee eeeeeeee eee eeeeeeee, eeeeeeee 8–8 e. Mee eeeee eeeeeee eee eeeeeee eeee Me8M, eeeeeeee ee eeeeee MeMe, eeeeeeeeeeee, eee eeeeeeee ee eeeee eeeeeeeeeeeeee.

8,8-Meeeee ‌88‌; Meeeeee Meeeeeeee:[‌88‌]

Mee eeeee ‌88‌ (8.8 eeee), [MeMe(MMMM)]8 (8 eee%), eee 8,8-eeeeeeeeeeeeee (8 eM) eeee eeeeeeeeee eeee e Meeeeee eeee ee e eeeeeeee. Mee eeeeeee eee eeeeeee eee 8 eee. MeMeM8 (8 eee%) eee eeeee eee e eeeeeeeeeee eee eeeeeeee. Mee eeeeeee eee eeeeeee ee ee eee eee eeeeeeee eee eeeeeeeee ee MMM, eeee eee eeeeeeeeeee eeeeeeee eeeeeeee ee 8–8 e. Mee eeeee eeeeeee eee eeeeeee eeee Me8M eee eeeeeeee ee eeeeee MeMe eeeeee eeeeeeeeeeee ee eeeee eeeeeeeeeeeeee.

α-Meeeeeeeee β-Meeee Meeeeeee ee Meeeeee ‌88‌; Meeeeee Meeeeeeee:[‌88‌,‌88‌]

Mee eeeee ‌88‌ (8.8 eeee), [MeMe(eee)]8 (8 eee%), (M)-MMMMM [(M)-‌88‌; 88 eee%], eee 8,8-eeeeeeeeeeeeee (8 eM) eeee eeeeeeeeee eeee e Meeeeee eeee ee e eeeeeeee. Mee eeeeeee eee eeeeeee eee 8 eee, eeee MeMeM8 (88 eee%) eee eeeee, eee e eeeeeeeeeee eee eeeeeeee. Mee eeeeeee eee eeeeeee ee ee eee eee eeeeeeee eee eeeeeeeee ee MMM, eeee eee eeeeeeeeeee eeeeeeee eeeeeeee ee 8–88 eee. Mee eeeee eeeeeee eee eeeeeee eeee Me8M eee eeeeeeee ee eeeeee MeMe eeeeee eeeeeeeeeeee ee eeeee eeeeeeeeeeeeee.

Mee-8-eeee Meeeeeeee ‌88‌; Meeeeee Meeeeeeee:[‌88‌]

Me e eeee eeeeeeeeee eee 8,8-eeeee eeeeeeeee ‌88‌ (8.88 eeee) eeeee eeeee eee eeeee 8.88 M [Me{(M)-MMMMM}]MeM8 ee 8,8-eeeeeeeeeeeeee ee eeeeeee (8.88 eM, 8 µeee). Mee eeeeeeeee eeeeeee eee eeeeeee ee 88 °M eee 88–88 e. Meeee eeeeeee ee eee eeeeeee ee e eeeeee ee eeeee, eee eeeeeee eee eeeeeeee ee eeeee eeeeee eeeeeeeeeeeeee (MeMMe/eeeeeee 8:8 ee 8:8).

8-Mee- eee 8-Meeeeeeeee[8.8.8]eeee-8-eeee ‌88‌ (M = MMe, M); Meeeeee Meeeeeeee:[‌88‌]

[MeMe(MMe8)M] [M = (M,M)-‌88‌; 8.888 eeee] eee Me[MMMM] {[MMMM]− = [8,8-(M8M)8M8M8]8M−; 8.888 eeee} eeee eeeee ee 8.8 M 8,8-eeeee ‌88‌ (8.88 eeee) ee 8,8-eeeeeeeeeeeeee, eee eee eeeeeee eee eeeeeee ee 88 °M eee 88 e. Mee eeeeeee eee eeee eeeeee eeeeeee e eeeee eeeeee ee eeeeee eee eeee eeeeee/MeMMe/Me8M (88:8:8) ee eeeeee. Meeee eeeeeeeeeee ee eee eeeeeee, eee eeeeeee eee eeeeeeeee ee eeeee eeeeee eeeeeeeeeeeeee (eeeeee eee, eeeeeee/MeMMe/MMMe8/Me8M 88:8:8:8) ee eeee eee eeeeeee.

Mee-8-eeeeeeeeeeeeeeeeeee ‌88‌ (M8 = M8 = Me); Meeeeee Meeeeeeee:[‌88‌]

M eeee ee 8,8-eeeee ‌88‌ (8.88 eeee), MMMM (8.8 eeee), [Me(eee)8][MeM8] (8.888 eeee), eee (M)-MMMMMMM [(M)-‌88‌; 8.888 eeee] ee 8,8-eeeeeeeeeeeeee (8 eM) eee eeeeee ee 88 °M eee 8 e. Mee eeeeeeeee eeee eee eeeeee ee ee, eeeeeee eeee eeeeeee, eeeeeeee eeeeeee e eeee ee eeeeee eee, eee eeeeeeeeeeee, eee eee eeeeeee eee eeeeeeee ee eeeeeeeeeeeeee (eeeeee eee).

Meeeeeeee Meeeeee ‌88‌; Meeeeee Meeeeeeee:[‌88‌]

Me e 8.8 M eeee ee eeeee ‌88‌ ee 8,8-eeeeeeeeeeeeee ee eeeeeee eeeeeeeeeee eee eeeee eee Me eeeeeeee (8 eee%) eee eee eeeeeeeeeeee eeeeee (8 eee%). Mee eeeeee eee eeeeee eeee M8 eee eee eeeeeee eee eeeeeee ee eeee eeeee ee eeeeeeeeee ee M8 eeeee eeeeeeee eeeeeeeeeee ee eeeee eee eeeeeeee. Me eeee eeeee, eee eeeeeee eee eeeeeeee eeee eeeeee eee eee eee eeeeeee eee eeeeeeee ee eeeeeeeeeeeeee (eeeeee eee).

References