Premium
A Laser Flash Photolysis Study on 2‐Azido‐ N,N ‐diethylbenzylamine − The Reactivity of Iminoquinone Methides in Solution
Author(s) -
Bucher Götz
Publication year - 2001
Publication title -
european journal of organic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.825
H-Index - 155
eISSN - 1099-0690
pISSN - 1434-193X
DOI - 10.1002/1099-0690(200107)2001:13<2463::aid-ejoc2463>3.0.co;2-6
Subject(s) - chemistry , flash photolysis , reactivity (psychology) , photodissociation , photochemistry , flash (photography) , laser , kinetics , optics , reaction rate constant , pathology , quantum mechanics , medicine , physics , alternative medicine
Photolysis of 2‐azido‐ N , N ‐diethylbenzylamine ( 1 ) in acetonitrile solution in the presence of various quenchers yields products of common nitrene chemistry (that is, derived from a didehydroazepine or a triplet nitrene), together with products arising from trapping of stereoisomeric iminoquinone methides. These intermediates are formed in a monophotonic process, by dediazotation of the precursor combined with a 1,4‐hydrogen shift. The reactivity of the iminoquinone methides (IQM) towards a variety of quenchers, including dienophiles and various nucleophiles, has been explored, using acetonitrile, DMF, and n ‐hexane as solvents. IQM reacts efficiently with electron deficient dienophiles [ k q (maleic anhydride) = 2.4·10 7 M −1 s −1 ], but not with simple olefins such as cyclohexene. IQM shows low to medium reactivity towards simple primary or secondary amines [ k q ( n ‐propylamine) = 6.4·10 4 M −1 s −1 ], medium reactivity with sterically unhindered simple alcohols [ k q (methanol) = 4.6·10 6 M −1 s −1 ], and high to very high reactivity towards thiols [ k q ( n ‐dodecanethiol) = 1.1·10 9 M −1 s −1 ], diols, and triols [ k q (glycerol) = 1.5·10 8 M −1 s −1 ], and sugars [ k q ( D ‐glucose) = 1.0·10 9 M −1 s −1 ]. IQM also reacts rapidly with cytosine: k q (cytosine) = 3.4·10 8 M −1 s −1 , while the reaction with adenine or thymine is less efficient [ k q (adenine) = 6.4·10 7 M −1 s −1 , k q (thymine) = 7.7·10 6 M −1 s −1 ].