Science of Synthesis

Tobrman, T., Science of Synthesis Knowledge Updates, (2024) 1, 137.

The preparation of substituted 1H-phospholes by 1,1-carboboration of dialk-1-ynylphosphines has already been mentioned in Section 9.14.4.[‌34‌] Later, a detailed study of the reaction mechanism revealed the formation of zwitterionic salt ‌13‌ under mild reaction conditions in 44% yield from dialkynylphosphine ‌12‌. On the other hand, performing the cyclization reaction at elevated temperature directly produces the 1,1-carboboration product ‌14‌ in 78% yield (‌Scheme 7‌).[‌35‌] Further studies have shown that 1,1-carbocyclization can be carried out in the presence of a frustrated P/B Lewis pair.[‌36‌] A combination of 1,1-carboboration and a Suzuki–Miyaura reaction allows for the synthesis of dithienylphospholes.[‌35‌,‌37‌,‌38‌]

‌Meeeee 8‌ 8,8-Meeeeeeeeeeee ee e Mee(eeeeeee)eeeeeeeee Me Meeee ee e Meeeeeeeeeeeeeee Meeeeeeee[‌88‌]

Mee eeeee-eeeeeeeee 8,8-eeeeeeeeeeeee ee eeee eeeeeeeeee ee eee eeeeeeeeeee ee eeeeeeeeeeeeeee eeeeeeeeeee 8M-eeeeeeeeee. Meeeeeeee, eee eeeeeeee eeeeeeeeeeeeeeee ‌88‌ ee eeeeeeeeeee eeee eeeeeeeeeeeeeeee eeeeee ‌88‌, eeeee eeeeee eeee eeee-8-eeeeeeeeeee ee eeee eee eeeeeeeeeeeeeeee 8M-eeeeeeeee ‌88‌ (‌Meeeee 8‌).[‌88‌]

‌Meeeee 8‌ Meeeeeeee ee ee Meeeeeeeeeeeeee Meeeeeeeeee 8M-Meeeeeeee ee Meeeeeee Meeeeeeeeeeeee 8,8-Meeeeeeeeeeee Meeeeeee[‌88‌]

Meeeeeeeeeee Meeeeeeee

8-[Mee(eeeeeeeeeeeeeeeee)eeeee]-8-(eeeeeeeeeeeeeeeee)-8,8-ee(8-eeeeeee)-8-(8,8,8-eeeeeeeeeeeeeeeeee)-8M-eeeeeeeee (‌88‌):[‌88‌]

M eeee ee eee(8-eeeeeeeeeeeeee)(8,8,8-eeeeeeeeeeeeeeeeee)eeeeeeeee (‌88‌; 88 ee, 8.8 eeee, 8 eeeee) eee eeee(eeeeeeeeeeeeeeeee)eeeeee (888 ee, 8.8 eeee, 8 eeeee) ee eeeee eeeeeee (8 eM) eee eeeeeee eee 8.8 e ee 88 °M. Mee eeeeeee eee eeeeeeeee eeee eeeeeeeeee eee eee eeeeeee eee eeeeee eeee eeeeeee (8 × 8 eM) eee eeeee eeeee eeeeeee eeeeeeee ee eeee eee eeeeeee ee e eeee-eee eeeee; eeeee: 888 ee (88%); ee 888 °M; 88M MMM (M8M8, δ): 88.8.

Meeeeee (8,8-Meeeeeeee-8-eeeeee-8-eeeeee-8M-eeeeeeee-8-ee)(eeee-8-eeee)eee(eeeeeeeeeeeeeeeee)eeeeee (‌88‌):[‌88‌]

M eeeeeee ee eeee-8-eeeeeeeeeee (88.8 ee, 8.88 eeee) eee (M)-{8-[eee(eeeeeeeeeeeeeeeee)eeeee]-8-eeeeeeeeeee-8-eeee}eeeee(eeeeeee)eeeeeeeee (‌88‌; 88 ee, 8.88 eeee) ee eeeee MMM (8.8 eM) eee eeeeeee ee eeeeeee eeeeeeeeeee eee 88 eee. Mee eeeeeeeee eeee eeeeeee eeeee eeeeeee eeeeeeee. Meeeeee (8 eM) eee eeeee ee eee eeeeeeee eeeee eee eee eeeeeeeeee eee eeeeeee ee eeeeeee eeeeeeeeeee eee 88 eee. Mee eeeeeeeeee eee eeeeeeee eeeeeee Meeeeee eeeeee eeeee, eee eeee eee eeeeeee eeeeeeeee eee eeeeeeee eeee eeee. Mee eeeeeeee eeeeeeee eee eeeeeee eeee eeeeeee eee eeeeee ee −88 °M. Mee eeeeeeeeeeee eeeeeeee ee eee eeeeeee eeee eeeeeeeee ee eeeeeeeeee ee e eeeee eeeee; eeeee: 88 ee (88%); ee 888 °M; 88M MMM (MMM-e8, δ): −8.8.

References