52428-35-0

Upstream product

• 51990-81-9 7-Diphenylmethyl-cycloheptatrien-(1,3,5) 
• 27081-10-3 tropylium tetrafluoroborate 
• 90-99-3 diphenylchloromethane 
• 900-91-4 3,3,3-triphenylpropionic acid 
• 42365-04-8 triphenylacetaldehyde 
• 873990-13-7 (2,2,2-triphenyl-ethyl)-carbamic acid ethyl ester 
• 898-46-4 2-diazo-1,1,1-triphenyl-ethane 

Downstream Products

• 67369-66-8 C₈H₆(C₆H₅)2Fe(CO)3 
• 65927-28-8 (diphenylmethylene)cycloheptane 
• 65927-32-4 3-Benzhydryl-7-butyl-cyclohepta-1,3,5-triene 
• 65927-31-3 3-Benzhydrylidene-6-butyl-cyclohepta-1,4-diene 

Relevant academic research and scientific papers

102. Solvolysen von 4-Alkylidenbicyclohept-2-en-6-olen. Synthese von 1-Vinylfulvenen und 8,8-Diphenylheptafulven

Solvolysis of 4-Alkylidenbicyclohept-2-en-6-oles.Synthesis of 1 Vinylfulvenes and 8,8-Diphenylheptafulvene.Four 4-alkylidenebicyclohept-2-en-6-ones 2-5, obtained via ketene cycloaddition to fulvenes, were reduced to separated mixtures of the 'endo'-alcohols 'endo'-6 to 'endo'-9 (68-73 percent) and 'exo'-alcohols 'exo'-6 to 'exo'-9 (3-20 percent).Treatment of some of these alcohols with (CF3SO2)2O in CH2Cl2/pyridine caused a spontaneous solvolysis to yield unsaturated 7-membered rings as pyridinium triflates 10-12 or 1-vinylfulvenes 13 and 14, a new class of reactive tetraenes: Both 'endo'-9 and 'exo'-9, having two methyl groups at C(7), were converted into the vinylfulvene 13 (ca. 80 percent).The alcohols with two H-atoms at C(7) exhibited a stereochemically controlled reaction selectivity, inasmuch as 'endo'-6 to 'endo'-8 afforded only the corresponding 7-membered-ring pyridinium salts 10-12 (66-79 percent), while 'exo'-6 produced only the vinylfulvene 14 (77 percent).A stereoelectronic control argument explains the C(1),C(5)-bond cleavage with 'endo'-B and 'endo'-6-'endo'-8, as well as the C(1),C(7)-bond cleavage with 'exo'-B, 'exo'-6, and with both 'endo'- and 'exo'-9.Thermolysis (120 deg) of the pyridinium triflates 10 and 11 yielded the 3-isopropenyl-cycloheptatrienes 18 and 19, respectively (ca. 90 percent); similar conditions (145 deg) applied to the triflate 12 produced the doubly cyclized fluorene derivative 21 (60 percent).When the iodide 22 derived from the triflate 12 with NaI was heated in refluxing toluene, 8,8-diphenylheptafulvene (23, 86 percent) was obtained.

Rearrangement Reactions of Tritylcarbenes: Surprising Ring Expansion and Computational Investigation

As a rule, acetylides and sulfonyl azides do not undergo electrophilic azide transfer because 1,2,3-triazoles are usually formed. We show now that treatment of tritylethyne with butyllithium followed by exposure to 2,4,6-triisopropylbenzenesulfonyl azide leads to products that are easily explained through the generation of short-lived tritylethynyl azide and its secondary product cyanotritylcarbene. Furthermore, it is demonstrated that tritylcarbenes generally do not produce triphenylethenes exclusively, as was stated in the literature. Instead, these carbenes always yielded also (diphenylmethylidene)cycloheptatrienes (heptafulvenes) as side products. This result is supported by static DFT, coupled cluster, and ab initio molecular dynamics calculations. From these investigations, the fused bicyclobutane intermediate was found to be essential for heptafulvene formation. Although the bicyclobutane is also capable of rearranging to the triphenylethene product, only the heptafulvene pathway is reasonable from the energetics. The ethene is formed straight from cyanotritylcarbene.