Science of Synthesis

Huang, Y.; Dömling, A., Science of Synthesis: Multicomponent Reactions, (2014) 1, 538.

Stadler and co-workers have applied a microwave-assisted one-pot Gewald reaction for the rapid generation of a 24-member library of thiophenes ‌24‌.[‌16‌] Six cyclic ketones, four nitriles, and elemental sulfur were employed for this protocol under microwave irradiation for 10 min at 120 °C in ethanol in the presence of morpholine; some examples are shown in ‌Scheme 10‌. The members of this thiophene library are synthesized in 22–87% yields and excellent purities.

‌Meeeee 88‌ Meeeeeeee-Meeeeeee Meeeeeee Meeeeeeee ee Meeeeeee-8-eeeeee[‌88‌]

‌Meeeeeeeeee 88‌

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

‌Meeeee 88‌ Mee-Mee eee Meeeeeee Meeeee Meeeeeeee eeeee Meeeeeeee Meeeeeeeeee[‌88‌]

Meeee eee ee-eeeeeee eeee eeeeeeee e eeeeeeeee-eeeeeeee Meeeee eeeeeeee ee eeeeeeeeeeeeeeeee ‌88‌, eeeee eee eeeeeeeeeee eeee eeeee eeeee eeee eee eeeeeeeeeeeee eeeeeeeeee eeeee ee eeee eeee eeeeee.[‌88‌] Meee eeeeee eeeeeee eee eeeeeeeeeee ee 8,8-eeeeeeeeeeeee eeeeeeee-8-eeeeee ‌88‌ ee e eeeeeee eeee eee eeee eeeeee eeeeee eee eeeeeeee eeee eee eeeeeeeee eeeeeeeeee. Meee eeeeeeee eee eeeee ee ‌Meeeee 88‌.

‌Meeeee 88‌ Meeeeeeee-Meeeeeee Meeeeeeee ee 8,8-Meeeeeeeeeeee Meeeeeee-8-eeeeee[‌88‌]

‌Meeeeeeeeee 88‌

Mee eeeeeeeee-eeeeeeeeeee Meeeee eeeee-eeeeeeeee eeeeeeee eeeee eeeeeeeee eeeeeeee eeeeeeeeeee ee eeeeeee (MM–eeeeeee) ee eeeeeeee eee eeee eeeeeeee (‌Meeeee 88‌).[‌88‌] Mee eeeeeeee eeeee eeeeee ee eeeeeeeee eeeeeeee ee eeeeeee eeeeee ee ee eeeeeee eeeeeee eeeee eeeeeeee eeee ee eee eeeeeeeee ee ‌88‌. Meeeeeee eee Meeeee eeeee-eeeeeeeee eeeeeeee eeeeeeee eeee eeeee eeeeeeeeeeee eeeeeee ee eeeeeeeee eeeeeee, ee eee eeee eeeeeee eeeee eeeeeeeee eeeeeeeeeee eeee eeee eeeeeee eeeeeeee eeeee.

‌Meeeee 88‌ Meeeeeeee-Meeeeeeeeee Meeeee Meeee-Meeeeeeee Meeeeeee Meeee Meeeeeeee Meeeeeee Meeeeeeeeee ee Meeeeee[‌88‌]

‌Meeeeeeeeee 88‌

Meee eee ee-eeeeeee eeee eeeeeeeee e eeeeeeeee-eeeee eeeeeeeee ee eeeee eeeeeeeeeeeeeeee eeeeeeeeeeee ee eeeeeeeee, ee eeeee ee ‌Meeeee 88‌. Mee eee ee eeeeeeeeee eeeeee ee eeeeeeeee eeeeee eee eee eeeeeeeee ee 8-eeeeeeeeeeeeee-8-eeeeeeeeeeee ‌88‌ eeee eeeeeeeee eeeeeeeeeee eeeeeee ee eeeeee eeeeee eee eeee e eeeeeeeeeee eeeeeeeee ee eee eeeeeeee eeee eeeeeeee ee eeeeeeeeeeee eeeeeee. Mee eeeeeeeeeeeeee eeeeee ‌88‌ eee eeeeeeee eeee eee “M—M” eeeeeeeee eeeeeeeee ee eeeeee eeeeee[8,8-e]eeeeeeeee-8(8M)-eeee ‌88‌. Meeeeeeeeeee ee ‌88‌ eeeee eee 8-eeeeeeeeeeee[8,8-e]eeeeeeeeee eeeeeeeeeeeee, eeeee eee eeeeeeeeeee eeee eeeeeeeee eeeeee ‌88‌ eeee e eeeeeee ee eeeeeeeeeee eeeeeeee.[‌88‌] Mee eeee eeeee ee eeee eeeeeeeee eeeeeee eeeeeeeee eeeeeeeeeee eee eee eeeeee eeeeeeeee eeeeeeee eeee 8 eeeee.

‌Meeeee 88‌ Meeeeeeee-Meeee Meeeeeeee ee Meeeeeeeeeeeeeeee[‌88‌]

Meeeeeeeeeee Meeeeeeee

Meee-Meeee Meeeeeee-8-eeeeee ‌88‌; Meeeeee Meeeeeeee:[‌88‌]

Mee eeeeeeeee-eeeeeeee eeeeeeeee eee eeeeeee eee ee e Meeeeee 8888 eeeeeeeee eeeeeeeee eeeeeee (Meeee Meee MeeM). Meee eeee eee eeeeeeee eeee ee eeeeeeeeeee eeeeeee eee eee eeeeeee eeeeeeeeeee eeee eee eeeeeeeeeee eeeeee (88 ee, 8.88–8.88 eeee), eeeeeee (8.8 eeeee), eee eeeeeeeee eeeeee (8.8 eeeee). Meeeeee, eeeeeeeeee (8.8 eeeee) eee eee MeMM (8.8 eM) eeee eeeee. Mee eeeeeeee eeeeeeeeeee eeeeeeeeeee, Meeee 88MM8 eee eeeeeee eeee eee eeeeee ee eeee eeeee. Mee eeeee eeee eeeeee eee eeeeee eeeeeeeeeeeee, eeeeee ee ee 888 °M (8888 M eeeeeee eeeeee eeeee), eee eeee ee eeee eeeeeeeeeee eee ee eeeeeeeeee 88 eee. Meeee eeee eee eeee eeeeee, eee eeeee eeee eeeeee (eeee ee e eeee) eeee eee eeeeeeeeeee eeeeeee eeee, eee eee eeeeeeee eeee eeeeeeeee ee MMMM eeeeeeee. Me eeeeeee eee eeeeeeee, eee eeeeeeee eeee eeeeeeeeeeee eeeee eeeeeee eeeeeeee. Mee eeeeeee eee eeeeeeeee ee MMMM (8.88 eM eeee) eee eeeeeeee ee eeeeeeeeeee MMMM. Meeeee-eeeeee eeeeeeeee eee eeeeeeee ee eeeeeeeee eeeeee; eeeee: 88–88%.

Meeee 8-Meeeeeeeeeeeee-8-eeeeeeeeeeee ‌88‌ (M = MM8Me); Meeeeee Meeeeeeee:[‌88‌]

M eeeeee (8.88 eee), eeeeee (8.8 e; 8.88 eee), eeeee eeeeeeeeeeee (8.8 e; 8.88 eee), eee Me8MM (8.88 e; 8.88 eee) eeee eeeee eeeeeeee ee MeMM (8 eM) ee ee eeee, eeee, 888-eM eeeee eeeeee. Mee eeeeee eee eeeeeeeeee eeee eeeeeeeeee ee 888 M eee 8–8 eee. Meee eeeeeeee, eee eeeeeee eeeeeeee eee eeeeeee eeeeeee, eeeee eee eeeeeeeee ee eeeeeeeeee, eeeeee eeee eeeeeee ee MeMM, eee eeeee.

8-Meeeeeeeeeee-8-eeeeee ‌88‌; Meeeeee Meeeeeeee:[‌88‌]

M eeeeeee ee ee eeeeeeeeeeeeeeee ‌88‌ (8 eeee), ee eeeeeeeee eeeeeee (8 eeee), eeeeee (8.8 eeee), eee eeeeeeeeee (8.8 eM) ee MeMM (8 eM) eee eeeeeeeee ee eeeeeeeee eeeeeeeeeee eee 88 eee ee 88 °M (eee eeeee 88 M). Meeee eeeeeee, eee eeeeeeeeeeee eeeeeee eee eeeeeeeee ee eeeeeeeeee, eee eee eeeeeeee eee eeeeee eeee M8M (88 eM). Meee e eeeeeeeeeee eeeeeeee, ee eee eeeeeeeee ee eeeeeeeeee, eeeeee eeee M8M (8 eM), eee eeeee ee ee. Meee e eeeeeee eeeeeee eeeeeeee, eee eeeeeee eee eeeeeeeee eeee MM8Me8 (8 × 88 eM). Mee eeeeeeee eeeeeee eeeeee eeee eeeee (MeMM8) eee eeeeeeee, eee eee eeeeeee eee eeeeeeeeee ee eeeee eee eeeee eeeeeee, eeeee eee eeeeeeee ee eeeeee eeeeeeeeeeeeee (MeMMe/eeeeeeeeeee 8:8).

Meeee 8-Meeee-8,8,8,8-eeeeeeeeeeeeeee[e]eeeeeeeee-8-eeeeeeeeeee [‌88‌, M8,M8 = (MM8)8, M = MM8Me]; Meeeeee Meeeeeeee eeeee Meeeeeeee Meeeeeeeeee:[‌88‌]

Meeeeeeeeeeee (8.88 e, 88 eeee), eeeee eeeeeeeeeeee (8.88 e, 88 eeee), eeeeee (8.88 e, 88 eeee), MM–eeeeeee (8:8 e/e; 8.8 e), eee eee MeMM (8.8 eM) eeee eeeee eee eeeeee ee e 88-eM eeeeeeee eeee. Mee eeeeeee eee eeeeeeeee ee eeeeeeeee eeeeeeeeeee (MMM Meeeeeee, 888 M, 888 eee, 888 °M) eee 8.8 eee (ee eeeeeeee) eee eeee eeeeeee eeee MM8Me8 (8 eM) eee eeeeeeee. Mee eeeee eee eeeeee/eeeeeeeeee eeee MM8Me8 (8 × 8.8 eM) eee eee eeeeeeee eeeeeeee eeee eeeeeeeeeeee eee eeeeeeee ee eeeeee eeeeeeeeeeeeee ee eeeeee e eeee eeeeee eeeee; eeeee: 8.88 e (88%).

Meeeee[8,8-e]eeeeeeeee-8(8M)-eeee ‌88‌; Meeeeee Meeeeeeee:[‌88‌]

M eeeeeee ee eeeee 8-eeeeeeeeeeeeee-8-eeeeeeeeeee ‌88‌ (8.88 eee) eee eeeeeeeee (88 eM) eee eeeeeeeeee ee 888 M eee 88–88 eee ee e eeeeeeeee eeeeeeeeeee. Mee eeeeeee eee eeeeeee ee eeee ee ee, eee eeee eeeeee eeee eee eeeee. Mee eeeeeeeee eeeeeeeeeeee eeeee eee eeeeeeeee ee eeeeeeeeee, eeeeee eeee eeeeeee M8M, eee eeeee. Mee eeeee eeeeeee eee eeeeeeee ee eeeeeeeeeeeeeeeee [MeMM/MMM (88:8)].

References