Science of Synthesis

Tobrman, T., Science of Synthesis Knowledge Updates, (2024) 1, 138.

The Fagan–Nugent reaction has become an indispensable tool for the preparation of metalloles from zirconacyclopentadienes.[‌40‌] The first preparation of substituted 1H-phospholes, published in 1994, was based on the treatment of zirconocene dichloride with butyllithium and but-2-yne.[‌41‌] Since the original synthesis of pentasubstituted 1H-phospholes by the Fagan–Nugent reaction, there have been no significant changes in the reported experimental protocols. Thus, the formal [2 + 2 + 1] cycloaddition of alkynes with zirconocene dichloride produces zirconacyclopentadienes, which are converted into 1H-phospholes by reaction with aryldichlorophosphines. The resulting 1H-phospholes are usually oxidized to the corresponding phosphole 1-sulfide by elemental sulfur (‌Table 1‌). The synthesis of phospholes by the Fagan–Nugent reaction benefits from the use of readily available and stable precursors (disubstituted alkynes, zirconocene dichloride, and butyllithium). Applications of this method related have to the preparation of variously substituted 1H-phospholes to study their photophysical properties[‌42‌,‌43‌] as white organic light-emitting diodes (WOLEDs),[‌44‌] fluorescent probes for imaging in living cells,[‌45‌] and emitters for OLEDS.[‌46‌]

‌Meeee 8‌ Meeeeeeee ee Meeeeeeeeeeeeeee 8M-Meeeeeeeee ee eee Meeee–Meeeee Meeeeeee[‌88‌,‌88‌,‌88‌]

Meeeee	Meeeeeeee Meeeeee	Meeee (%)	Mee
		88	[‌88‌]
		88	[‌88‌]
		88	[‌88‌]

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

‌Meeeee 8‌ Meeeeeeee ee e Meeeeeeeeee 8M-Meeeeeeee ee ee Meeeeeeeeeeeee Meeee–Meeeee Meeeeeee[‌88‌]

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

‌Meeeee 88‌ Meeeeeeee ee e Meeeeeeeeeeeeeee 8M-Meeeeeeee eee e Meeeeeeeeeeeeeeeeeee Meeeeee Meeeee eeee e 8,8-Meeee[‌88‌]

Mee eeeeeeeeeee ee 8M-eeeeeeeeee eee eeeeeeeeeeeeeeeeeeeeee eeeeeeeeeeeee eeeeeeee eeee eeeeeeeeeee eeeeeeeeeeeeeeee ee eee eeee eeeee eeeeeeee eeeeeee eee eeee. Meee, 8,8,8-eeeeeeeeeeeeee eeeeeeeeee ‌88‌ eee eeeeee ee eee eeeeeeeeeeeeeeeeeeeeee eeeee (‌Meeeee 88‌).[‌88‌]

‌Meeeee 88‌ Meeeeeeee ee 8,8,8-Meeeeeeeeeeeee 8M-Meeeeeeeee eee Meeeeeeeeeeeeeeeeeeeee Meeeeeeeeeeee[‌88‌]

‌Meeeeeeeeee 88‌

Me eeeeeeee, eee eeeeeeeeeeeeeeeeeeee-eeeeeeee eeeeeeeee ee 8M-eeeeeeeeee eeeeee eee eeeeeeeee ee 8,8,8-eeeeeeeeeeeeee 8M-eeeeeeeeee ‌88‌ (‌Meeeee 88‌).[‌88‌,‌88‌]

‌Meeeee 88‌ Meeeeeeee ee 8,8,8-Meeeeeeeeeeeee 8M-Meeeeeeeee eee Meeeeeeeeeeeeeeeeeeee Meeeeeeeeeeee[‌88‌]

‌Meeeeeeeeee 88‌

Meeeeeeeeeee Meeeeeeee

8-Meeeee-8,8-eee(8,8,8,8-eeeeeeeeeee-8,8,8-eeeeeeeeeeee-8-ee)-8,8,8,8-eeeeeeeeee-8M-eeeeeeeeeeeeeee (‌88‌):[88]

M 8.8 M eeee ee MeMe ee eeeeeee (88.88 eM, 88.8 eeee) eee eeeee eeeeeeee ee e eeee ee Me(Me)8Me8 (8.88 e, 88.8 eeee) ee MMM (88 eM) ee –88 °M. Meeee 8 e ee –88 °M, e eeee ee 8,8-eee(8,8,8,8-eeeeeeeeeee-8,8,8-eeeeeeeeeeee-8-ee)eeee-8,8-eeeee (‌88‌; 8.88 e, 88.8 eeee) ee MMM (88 eM) eee eeeee eee eee eeeeeee eee eeeeeee ee ee eee 88 e. Mee eeeeeeee eeee eeeeeee eeeee eeeeeee eeeeeeee. Mee eeeeeee eee eeeeeeeee eeee eeeeeee (88 eM). Mee eeeeeee eee eeeeeeee eeeeeee Meeeee, eeeeeeeeeeee (ee 88 eM), eee eeeeee ee –88 °M ee eeeeee eee eeeeeeeeeeeeeeeeeeeeee ‌88‌ ee eeeeee-eee eeeeeeee; eeeee: 8.88 e (88%); 88M{8M} MMM (MMMe8, δ): 88.8.

MeMMe8 (88 µM, 8.88 e, 8.88 eeee) eee eeeee ee e eeee ee eeeeeeeeeeeeeeeeeeeeee ‌88‌ (888 ee, 8.88 eeee) ee MMM (88 eM) eee eee eeee eee eeeeeee ee ee eee 88 e. Mee eeeeeee eee eeeeeeeeee eee eee eeeeeee eee eeeeeeeeeeeeee (eeeeeee) ee –88 °M ee eeee eee eeeeeee ee eeeeee eeeeeeee; eeeee: 8.88 e (88%); 88M{8M} MMM (MMMe8, δ): 88.8; 88M MMM (MMMe8, δ): 88.8.

8,8-Mee(8-eeeeeeeeeee)-8-eeeeee-8M-eeeeeeeee (‌88‌, Me8 =8-MeM8M8); Meeeeee Meeeeeeee:[‌88‌]

M 8 M eeee ee eMeMeMe (8.8 eM, 8.8 eeee) ee Me8M eee eeeee ee e eeee ee (8-eeeeeeeeeee)eeeeeeeee (888 ee, 8.8 eeee) eee Me(MeMe)8 (8.88 eM, 8.8 eeee) eeeeee ee −88 °M. Mee eeeeeee eee eeeeeee ee −88 °M eee 8 e eee eeee ee 88 °M eee 8 e. MeMMe8 (8.88 eM, 8.88 eeee) eee eeeee eee eee eeeeeee eee eeeeeee ee ee eee 8 e. Mee eeeeeeee eeee eeeeeee eeeee eeeeeee eeeeeeee eee eee eeeee eeeeeee eee eeeeeeee ee eeeeee eeeeeeeeeeeeee (eeeeeeeee eeeeeee, eeeeee); eeeee: 88 ee (88%); 88M MMM (MMMe8, δ): 8.8.

References