Science of Synthesis

Gandon, V.; Thorimbert, S.; Malacria, M., Science of Synthesis, (2009) 46, 214.

Palladium is a versatile transition metal which has been used extensively to perform cycloisomerizations.[‌125‌–‌127‌] In 1985 the use of palladium(II) complexes for the carbocyclization of 1,6-enynes ‌144‌ into five-membered-ring exocyclic 1,3-dienes ‌145‌ was reported for the first time,[‌128‌] and since then this work has been the subject of further studies.[‌129‌–‌132‌] Most of the results obtained have been reviewed from a synthetic[‌133‌,‌134‌] and a mechanistic point of view.[‌135‌–‌137‌] In general, the reactions of 1,6-enynes give a mixture of 1,4- and 1,3-dienes, but 1,4-dienes with certain substitution patterns can be formed exclusively when specific catalysts are employed (‌Scheme 49‌).[‌128‌–‌131‌]

‌Meeeee 88‌ Meeeeeeee(MM)-Meeeeeeee Meeeeeeeeeeeeeeeee ee 8,8-Meeeee[‌888‌–‌888‌,‌888‌]

‌Meeeeeeeeee 88‌

M8	M8	M	Meeeeeee	Meeee (%)	Mee
MM	MM8MMMMMM	MMe8	M	88	[‌888‌]
MMMM	MM8MMMMMM	MMe8	M	88	[‌888‌]
M	MM8MMMMMM	MMe8	M	88	[‌888‌]
M	Me	M(MM8Me)8	M	88	[‌888‌,‌888‌]
M	Me	M(MM8Me)8	M	88	[‌888‌]
M	M	MMe	M	88	[‌888‌]
M	MM8MMMMMM	MMe	M	88	[‌888‌]
M		M(MM8Me)8	M	88	[‌888‌]

Meeeeeeeee eee eeeeeeee eeeeeee eeee eee eeeeeeeeeee ee 8,8-eeeeee ‌888‌ eeee eeee eeeeeeee, eee eeeee eeeeeeeee ee eeeeeee eeeeeeeeeeeeeeeeeee ee 8,8-eee(eeeeeeeeee)eeeeeeeeeeee ‌888‌ ee eeee eeeeee ee eeeeeee eeee e eeeeee eeeeeeeee eeeeee [eeee(eeeeeeeeeeeeeeeeeeee)eeeeeeeeeee(8)], ee eeee eeeeeeeee, eee eeeeee e eeeeeeeeee ee e eeeeeeee eeee; eeee eeeeeee eee eeeeeeee eeee eee-8-eeeeeeeeeeeeee eee eeeeee eeee (‌Meeeee 88‌).[‌888‌]

‌Meeeee 88‌ Meeeeeeee-Meeeeeeee Meeeeeeeeeee ee 8,8-Meeeee[‌888‌]

Meeeeeeeeeee Meeeeeeee

Meeeeeee (8M)-8-(Meeeeeeeeeeeeeeeeee)-8-eeeeeeeeeeeeeeeeeeeee-8,8-eeeeeeeeeeeee [‌888‌, M8 = M; M8 = Me; M = M(MM8Me)8]; Meeeeee Meeeeeeee:[‌888‌]

Meeeee M: M eeeeee eeee eeeeeeee ee eeeeee Me(MMe)8 (8 ee, 8.888 eeee) eee Me8M (8 ee, 8.888 eeee) eee eeeee ee eee eeeee ‌888‌ [M8 = M; M8 = Me; M = M(MM8Me)8; 88 ee, 8.888 eeee)] ee eeeeeee (8.88 eM) (MMMMMMM: eeeeeeeeee), eee eee eeeeeeeee eeeeeee eee eeeeee ee 88°M eee 8 e. Meeee eeeeeee, eee eeeee eeeeeeee eee eeeeeeee eeeeeeee eeee eee eeeee eeeeeee ee eeeeeeeeeeeeee (eeeeee eee) ee e eeeee eee; eeeee: 88 ee (88%).

References