Trimethylene methane

Methylanecyclopentane lormation from siloxymelhylallylsilane or acetoxymelhylattylwlane 4 wit i Micfiael acceptor olefins and Pd catalysts (via trimethylene methane equivalent)... 

A number of diradicals (also called biradicals) are known. When the unpaired electrons of a diradical are widely separated (e.g., as in CH2CH2CH2CH2 ), the species behaves spectrally like two doublets. When they are close enough for interaction or can interact through an unsaturated system (as in trimethylene-methane, " they... 

Chan and Li reported that conjugated 1,3-butadienes were produced in moderate yields when carbonyl compounds reacted with 1,3-dichloropropene and zinc in water (Eq. 8.29).61 The use of 3-iodo-1-chloropropene instead of 1,3-dichloropropene greatly improved the yields. When the reactions were interrupted after their initial allyla-tions, subsequent base treatment of the intermediate compounds produced vinyloxiranes in high yields. Similarly, reactions of carbonyl compounds with 3-iodo-2-chloromethyl-l-propene followed by base treatment produced 2-methylenetetrahydrofurans (Eq. 8.30).62 Thus, the 3-iodo-2-chloromethyl-l-propene served as a novel trimethylene-methane equivalent.63... 

Y-conjugated derivatives of trimethylene methane (87) and a,a -acetonediyl dianions (88) give good yields of expected mono- and di-substitution products on... 

Deuterium atoms statistically scrambled among the trimethylene methane carbon atoms. 

Pioneering work of Dowd on trimethylene methane [142], 1,8-naphthoquinodi-methane diradicals were among the first examples of non-Kekule 7r,7r-diradicals that were found to be persistent in their triplet ground state at cryogenic temperatures and were thoroughly characterized by various spectroscopic methods [143], Time resolved studies of diradicals have provided lifetimes and reactivities of numerous diradical intermediates in solution [144], y-irradiation of CAN, 68, in haloalkane glasses at 77 K yielded radical cation 68 + its electronic absorption spectrum has been obtained and represents first report of absorption spectrum of an ionized diradical [145]. Irradiation at >640 nm converted it into an isomer identical with that formed by ionization of 1,4-dihydro-l,4-ethanonaphtho[l,8-rfe][l,2]diazepine 70, and subsequent irradiation of the radical cation at A > 540 nm. Results identified the photo isomer of 68 + to be 69 + (Scheme 4). 

The strain energy of methylenecyclopropane (2) exceeds" that of cyclopropane by about 13 kcal mol "S a value similar to the excess strain in 1,1-difluorocyclopropane. This is certainly a part of the propensity for ring-opening although the stability of trimethylene-methane (3) is undoubtedly the more important factor (cf. equation 3). Similarly, the ringopening facility of cyclopropanone (see Chapter 23 by Wasserman and coworkers) partially reflects additional ring strain. 

TRIPOD LIGANDS WITH A TRIMETHYLENE-METHANE BACKBONE 298... 

Formation of heterocycles in Pd-catalyzed cycloadditions involving trimethylene-methane and its analogs 02MI6. 

Harrington PJ (1995) Transition metal allyl complexes trimethylene methane complexes. In Abel EW, Stone FGA, Wilkinson G (eds) Comprehensive organometallic chemistry, vol 12, Chap 8.4. Pergamon, Oxford, p 923... 

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