Science of Synthesis

Yamazaki, T., Science of Synthesis Knowledge Updates, (2017) 2, 288.

Decarboxylative allylation occurs in the presence of the tris(dibenzylideneacetone)dipalladium(0) complex and the chiral ligand (S)-2-{2-(diphenylphosphino)phenyl}-4-tert-butyl-4,5-dihydrooxazole [(S)-t-Bu-PHOX, ‌21‌] if β-keto ester ‌22‌[‌16‌–‌18‌] or its regioisomeric enol carbonate ‌25‌ is employed as the substrate to give 2-allyl-2-fluorodihydronaphthalen-1-one ‌23‌ (‌Scheme 11‌).[‌19‌] In addition, analogues of ‌25‌, such as enol silyl ether ‌24‌,[‌20‌] lead to the construction of the identical product ‌23‌ in excellent yields with excellent enantiomeric purities. A very interesting feature of these processes is that successful results, especially in terms of the enantiomeric selectivity and the chemical yield, are highly dependent on the molar ratio between ligand ‌21‌ and the palladium catalyst. For example, ‌23‌ is obtained in 94% yield with 93% ee by transformation of ‌22‌ using a ligand ‌21‌/palladium ratio of 1.25:1, but it is obtained in only 50% yield with 89% ee using a 1:4 ratio of ligand ‌21‌/palladium.

‌Meeeee 88‌ Meeeeeeee-Meeeeeeee Meeeeeeee ee (M)-8-Meeeee-8-(eeee-8-eeee)-8,8-eeeeeeeeeeeeeeeee-8(8M)-eee[‌88‌,‌88‌,‌88‌]

Meeeeeeeeeee Meeeeeeee

(M)-8-Meeee-8-eeeeee-8,8-eeeeeeeeeeeeeeeee-8(8M)-eee (‌88‌); Meeeeee Meeeeeeee eee eee Meeeeeeeeeeeeeee Meeeeeeeeeeeeee Meeeeeeeee ee β-Meee Meeee ‌88‌:[‌88‌]

M 88-eM, eee-eeeeee, eeeee-eeeeeeee eeeee eeeeeeee eeee e eeeeeeee eeeeeee eee eee eeeee eeeee eeeee eeeeeee eeeeeeee, eeeeee ee ee, eee eeeeeee eeee Me8(eee)8 (88.8 ee, 8.888 eeee, 8.8 eee%) eee (M)-e-Me-MMMM (‌88‌; 88.8 ee, 8.8888 eeee, 8.88 eee%) eeeee ee eeeeeeeeee ee eeeee. Mee eeeeee eee eeeeeeeee eeeeee eee eeeeeee eeee eeeee (8 ×), eee eeee MMM (88 eM) eee eeeee. Meeee eee eeeeeee eee eeee eeeeeee eee 88 eee, eeeee 8-eeeeee-8-eee-8,8,8,8-eeeeeeeeeeeeeeeeeeeee-8-eeeeeeeeeee (‌88‌; 888 ee, 8.8 eeee) eee eeeee eeeeeeee ee eeeeeee. Mee eeeeeeeee eeee eee eeeeeee ee 88 °M eee 8 e (eeee eeeeeeeeee eeeeeee ee MMM eee MM) eee eeee eee eeeeeee eee eeeeeeeeee eeeee eeeeeee eeeeeeee. Meeeeeeeeeee ee eeeeee eeeeeeeeeeeeee (eeeeee eee, eeeeee/Me8M 88:8) eeee eee eeeee eeeeeeee ee e eeeeeeeee eee; eeeee: 888.8 ee (88%);88M MMM (MMMe8, 888 MMe, δ): −888.8.

(M)-8-Meeee-8-eeeeee-8,8-eeeeeeeeeeeeeeeee-8(8M)-eee (‌88‌); Meeeeee Meeeeeeee eee eee Meeeeeeeeeeeeeee Meeeeeeeee ee Meee Meeee Meeee ‌88‌:[‌88‌]

M 88-eM eeeee eee eeeeeee eeee Me8MMeM8Me8 (88.8 ee, 8.888 eeee), (M)-e-Me-MMMM (‌88‌; 8.8 ee, 88 μeee) eee Me8(η8-MM8MM=MM8)8Me8 (8.8 ee, 8.8 μeee) eeeeeeee ee eeeeeee (8 eM) eeeee ee eeeeeeeeee ee M8. Meeee eee eeeeeee eee eeee eeeeeee ee ee eee 88 eee, e eeee ee 8-eeeeee-8-(eeeeeeeeeeeeeee)-8,8-eeeeeeeeeeeeeeeeee (‌88‌; 88 ee, 8.88 eeee) eee eeeee eeeee eeeeeeeee (88 μM, 8.88 eeee) ee eeeeeee (8.8 eM) eee eeeee, eee eee eeeeeee eee eeeeee ee 88 °M eeeeeeeee. Mee eeeeeeee eee eeeeeeee ee eee eeeeeeee ee M8M eee Me8M. Mee eeeeee eeee eeeeeeeee, eee eee eeeeeee eeeee eee eeeeeeeee eeee Me8M (8 ×). Mee eeeeeeee eeeeeee eeeee eee eeeee (Me8MM8), eee eee eeeeeee eee eeeeeeeeee. Meeeeeeeeeee ee eeeee eeeeeeeeeeeeee (eeeeee/Me8M 88:8) eeeeeeee eee eeeee eeeeeeee ee e eeeeeeeee eee; eeeee: 88 ee (88%); 88% ee.

References