908094-04-2Relevant articles and documents
Complexes of [(dadi)Ti(L/X)]m That Reveal Redox Non-Innocence and a Stepwise Carbene Insertion into a Carbon-Carbon Bond
Heins, Spencer P.,Morris, Wesley D.,Cundari, Thomas R.,MacMillan, Samantha N.,Lobkovsky, Emil B.,Livezey, Nicholas M.,Wolczanski, Peter T.
, p. 3488 - 3501 (2018)
The addition of donors to (dadi)Ti(THF) (1-THF, dadi = [{-CH=N(1,2-C6H4)N(2,6-iPr2-C6H3)}2]n) afforded the adducts [(dadi)Ti(L/X)]m (1-L, m = 0, N2CPh2; m = -1, X = Cl-, N3-, OiPr-, CH3-, neoPe-, CH=CH2-, CCPh-, CCTMS-, H(D)-). In all adducts, the chelate was in the (dadi)4- redox state. For certain anions, evidence for intimate binding of the Li+ counterion was explored spectroscopically. Treatment of 1-THF with PhHCN2, yielded {PhC3H3(-NC6H4-2-NAr)2}Ti(THF) (3, Ar = 2,6-iPr2-C6H3), which contains a cyclopropanated dadi ligand. The mechanism was explored by calculations, and the addition of Ph2CN2 to 3 produced a nacnac derivative, {PhC(CHNC6H4-2-NAr)2}Ti(??2-HNNCPh2) (4, Ar = 2,6-iPr2-C6H3), generated via hydrogen transfer from the cyclopropane.
Continuous Flow Synthesis and Purification of Aryldiazomethanes through Hydrazone Fragmentation
Lévesque, éric,Laporte, Simon T.,Charette, André B.
, p. 837 - 841 (2017/01/14)
Electron-rich diazo compounds, such as aryldiazomethanes, are powerful reagents for the synthesis of complex structures, but the risks associated with their toxicity and instability often limit their use. Flow chemistry techniques make these issues avoidable, as the hazardous intermediate can be used as it is produced, avoiding accumulation and handling. Unfortunately, the produced stream is often contaminated with other reagents and by-products, making it incompatible with many applications, especially in catalysis. Herein is reported a metal-free continuous flow method for the production of aryldiazomethane solutions in a non-coordinating solvent from easily prepared, bench-stable sulfonylhydrazones. All by-products are removed by an in-line aqueous wash, leaving a clean, base-free diazo stream. Three successful sensitive metal-catalyzed transformations demonstrated the value of the method.
Preparation method of mild diazomethane derivative
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Paragraph 0115; 0119, (2017/08/28)
The invention discloses a preparation method of a mild diazomethane derivative. The preparation method comprises that EWG-substituted benzene sulfonyl chloride and hydrazine hydrate undergo a reaction to produce EWG-substituted benzene sulfonyl chloride, the EWG-substituted benzene sulfonyl chloride and aldehyde or ketone undergo a reaction to produce EWG-substituted benzenesulfonylhydrazone, and the EWG-substituted benzenesulfonylhydrazone, a base and an organic solvent are mixed and undergo a replacement reaction to produce a diazomethane derivative. The diazomethane derivative is not separated and purified and is further used for a tension small ring synthesis reaction and an insertion reaction. The benzene ring of benzenesulfonylhydrazone is introduced with an electron-withdrawing group EWG, and through electron effects and steric hindrance effects, the benzenesulfonyl group on the benzenesulfonylhydrazone is easily separated so that a diazomethane derivative is produced under very mild conditions and especially at the room temperature.
