9-diazofluorene

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: To probe the scope of the reaction even further, we investigated the synthesis of semi-stabilized diazo-compounds. Treatment of 9-azido-fluorene 2j with phosphine 1e under anhydrous conditions at low temperature (toluene, 0° C.), followed by loading the red solution directly on basic alumina (Grade 5) and eluting with 10% CH2Cl2/hexanes, 9-diazo-fluorene 5j was isolated in 85% yield and excellent purity (96%). Apparently, thermal fragmentation of the putative triazenophosphonium salt, which more than likely exists in its neutral λ5-phosphorane form[16] is suppressed sufficiently for this substrate under the reaction conditions. The low temperature and low polarity of the solvent probably contribute to that greater stability. Under the standard conditions (THF/H2O), incomplete conversion of the azide 2j and contamination of the diazo-compound 5j with substantial amounts of other products, probably arising from alternative triazene decomposition and dimerization of the diazo-compound, were apparent. Finally, a vinylogous diazo-carbonyl compound 5k (96% purity) was prepared in good yield from anthraquinone-based azide 2k using the standard conditions. is suppressed sufficiently for this substrate under the reaction conditions

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: To probe the scope of the reaction even further, we investigated the synthesis of semi-stabilized diazo-compounds. Treatment of 9-azido-fluorene 2j with phosphine 1e under anhydrous conditions at low temperature (toluene, 0° C.), followed by loading the red solution directly on basic alumina (Grade 5) and eluting with 10% CH2Cl2/hexanes, 9-diazo-fluorene 5j was isolated in 85% yield and excellent purity (96%). Apparently, thermal fragmentation of the putative triazenophosphonium salt, which more than likely exists in its neutral λ5-phosphorane form[16] is suppressed sufficiently for this substrate under the reaction conditions. The low temperature and low polarity of the solvent probably contribute to that greater stability. Under the standard conditions (THF/H2O), incomplete conversion of the azide 2j and contamination of the diazo-compound 5j with substantial amounts of other products, probably arising from alternative triazene decomposition and dimerization of the diazo-compound, were apparent. Finally, a vinylogous diazo-carbonyl compound 5k (96% purity) was prepared in good yield from anthraquinone-based azide 2k using the standard conditions. the scope of the reaction even further the synthesis of semi-stabilized diazo-compounds eluting with 10% CH2Cl2/hexanes

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: To probe the scope of the reaction even further, we investigated the synthesis of semi-stabilized diazo-compounds. Treatment of 9-azido-fluorene 2j with phosphine 1e under anhydrous conditions at low temperature (toluene, 0° C.), followed by loading the red solution directly on basic alumina (Grade 5) and eluting with 10% CH2Cl2/hexanes, 9-diazo-fluorene 5j was isolated in 85% yield and excellent purity (96%). Apparently, thermal fragmentation of the putative triazenophosphonium salt, which more than likely exists in its neutral λ5-phosphorane form[16] is suppressed sufficiently for this substrate under the reaction conditions. The low temperature and low polarity of the solvent probably contribute to that greater stability. Under the standard conditions (THF/H2O), incomplete conversion of the azide 2j and contamination of the diazo-compound 5j with substantial amounts of other products, probably arising from alternative triazene decomposition and dimerization of the diazo-compound, were apparent. Finally, a vinylogous diazo-carbonyl compound 5k (96% purity) was prepared in good yield from anthraquinone-based azide 2k using the standard conditions. the scope of the reaction even further the synthesis of semi-stabilized diazo-compounds eluting with 10% CH2Cl2/hexanes

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: To 9-fluorenone hydrazone (9.7 g, 0.05 moles) in 1,2-dichloroethane (50 ml) together with 1,1,3,3-tetramethylguanidine (26.4 ml) and iodine (2 ml, 1% w/v solution) was added peracetic acid solution (11.4 ml, 1.27 × 0.05 moles) over 25 minutes at 10° - 15°. The orange solution was stirred for 15 minutes at 15°, washed with water (5 × 250 ml) and made up to 250 ml in a volumetric flask. An aliquot (50 ml) treated with excess acetic acid yielded 193 ml gas corrected to NTP which corresponded to a 86.2% yield of diazoalkane. washed with water (5 × 250 ml) made up to 250 ml in a volumetric flask An aliquot (50 ml) treated with excess acetic acid

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: To probe the scope of the reaction even further, we investigated the synthesis of semi-stabilized diazo-compounds. Treatment of 9-azido-fluorene 2j with phosphine 1e under anhydrous conditions at low temperature (toluene, 0° C.), followed by loading the red solution directly on basic alumina (Grade 5) and eluting with 10% CH2Cl2/hexanes, 9-diazo-fluorene 5j was isolated in 85% yield and excellent purity (96%). Apparently, thermal fragmentation of the putative triazenophosphonium salt, which more than likely exists in its neutral λ5-phosphorane form[16] is suppressed sufficiently for this substrate under the reaction conditions. The low temperature and low polarity of the solvent probably contribute to that greater stability. Under the standard conditions (THF/H2O), incomplete conversion of the azide 2j and contamination of the diazo-compound 5j with substantial amounts of other products, probably arising from alternative triazene decomposition and dimerization of the diazo-compound, were apparent. Finally, a vinylogous diazo-carbonyl compound 5k (96% purity) was prepared in good yield from anthraquinone-based azide 2k using the standard conditions. is suppressed sufficiently for this substrate under the reaction conditions

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: To probe the scope of the reaction even further, we investigated the synthesis of semi-stabilized diazo-compounds. Treatment of 9-azido-fluorene 2j with phosphine 1e under anhydrous conditions at low temperature (toluene, 0° C.), followed by loading the red solution directly on basic alumina (Grade 5) and eluting with 10% CH2Cl2/hexanes, 9-diazo-fluorene 5j was isolated in 85% yield and excellent purity (96%). Apparently, thermal fragmentation of the putative triazenophosphonium salt, which more than likely exists in its neutral λ5-phosphorane form[16] is suppressed sufficiently for this substrate under the reaction conditions. The low temperature and low polarity of the solvent probably contribute to that greater stability. Under the standard conditions (THF/H2O), incomplete conversion of the azide 2j and contamination of the diazo-compound 5j with substantial amounts of other products, probably arising from alternative triazene decomposition and dimerization of the diazo-compound, were apparent. Finally, a vinylogous diazo-carbonyl compound 5k (96% purity) was prepared in good yield from anthraquinone-based azide 2k using the standard conditions. the scope of the reaction even further the synthesis of semi-stabilized diazo-compounds eluting with 10% CH2Cl2/hexanes

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: To probe the scope of the reaction even further, we investigated the synthesis of semi-stabilized diazo-compounds. Treatment of 9-azido-fluorene 2j with phosphine 1e under anhydrous conditions at low temperature (toluene, 0° C.), followed by loading the red solution directly on basic alumina (Grade 5) and eluting with 10% CH2Cl2/hexanes, 9-diazo-fluorene 5j was isolated in 85% yield and excellent purity (96%). Apparently, thermal fragmentation of the putative triazenophosphonium salt, which more than likely exists in its neutral λ5-phosphorane form[16] is suppressed sufficiently for this substrate under the reaction conditions. The low temperature and low polarity of the solvent probably contribute to that greater stability. Under the standard conditions (THF/H2O), incomplete conversion of the azide 2j and contamination of the diazo-compound 5j with substantial amounts of other products, probably arising from alternative triazene decomposition and dimerization of the diazo-compound, were apparent. Finally, a vinylogous diazo-carbonyl compound 5k (96% purity) was prepared in good yield from anthraquinone-based azide 2k using the standard conditions. is suppressed sufficiently for this substrate under the reaction conditions

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: To probe the scope of the reaction even further, we investigated the synthesis of semi-stabilized diazo-compounds. Treatment of 9-azido-fluorene 2j with phosphine 1e under anhydrous conditions at low temperature (toluene, 0° C.), followed by loading the red solution directly on basic alumina (Grade 5) and eluting with 10% CH2Cl2/hexanes, 9-diazo-fluorene 5j was isolated in 85% yield and excellent purity (96%). Apparently, thermal fragmentation of the putative triazenophosphonium salt, which more than likely exists in its neutral λ5-phosphorane form[16] is suppressed sufficiently for this substrate under the reaction conditions. The low temperature and low polarity of the solvent probably contribute to that greater stability. Under the standard conditions (THF/H2O), incomplete conversion of the azide 2j and contamination of the diazo-compound 5j with substantial amounts of other products, probably arising from alternative triazene decomposition and dimerization of the diazo-compound, were apparent. Finally, a vinylogous diazo-carbonyl compound 5k (96% purity) was prepared in good yield from anthraquinone-based azide 2k using the standard conditions. the scope of the reaction even further the synthesis of semi-stabilized diazo-compounds eluting with 10% CH2Cl2/hexanes