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Reactions with heterocumulenes

The oxidation of fV-carbamoylimidazolidine-2-thiones (281) has been used to prepare 2,3,5,6-tetrahydroimidazo[l,2-cf][l,2,4]thiadiazol-3-ones (282) which undergo cycloaddition reactions with heterocumulenes to give a variety of heteropentalenes (81T2485). [Pg.1016]

H. Cycloaddition Reactions with Heterocumulenes 1. Reaction with 3-Dimethylamino-2H-azirines... [Pg.194]

Zn(H)(Tpph,Me)], obtained from the reaction of [Zn(F)(Tpph Me)] with Et SiH, and [Zn(OH)(Tpph,Me)] undergo insertion reactions with heterocumulenes. CO, CS2, and RCNS insert into the Zn-H bond giving [Zn(OCH(0))(Tpph Me)], [Zn(SCH(S))(Tpph Me)], and [Zn(SCH(NR))(Tpph,Me)], respectively. [Zn(OH)(Tpph Me)] reacts with RCNS yielding [Zn(SC(0)NHR)(Tpph Me). In the presence of EtOH the reaction of [Zn(X)(Tpph,Me) with RNCS yields [Zn-(SC(NR)OEt)(Tpph Me). These compounds have been characterized by X-ray crystallography, supporting a four-center reaction mechanism proposed for hydrolytic zinc enzymes.145 [Zn(OH)-(Tpph,Me)] reacts with simple aminoacids to form [Zn(AB)(Tpph,Me)]... [Pg.309]

Aminotin species are readily hydrolyzed and react with protic reagents (Scheme 18). Substitution reactions occur with reactive halides (equations 83 and 84), as do addition reactions with heterocumulenes, e.g. 0=C=C=C=0... [Pg.4887]

Cycloadditions The [2+2] cycloadducts derived from sulfurdiimides are seldom isolated but exchange reactions with heterocumulenes, proceeding via a [2+2] cycloaddition sequence, are often observed. In the reaction of diphenylketene with di-tosylsulfurdiimide at -15 °C the [2+2] cycloadduct 58 is formed, while at 70 °C the [3+2]... [Pg.526]

See other pages where Reactions with heterocumulenes is mentioned: [Pg.169]    [Pg.122]    [Pg.140]    [Pg.160]    [Pg.159]    [Pg.180]    [Pg.761]    [Pg.55]    [Pg.274]    [Pg.45]    [Pg.45]    [Pg.81]    [Pg.157]    [Pg.177]    [Pg.198]    [Pg.253]    [Pg.276]    [Pg.3302]    [Pg.170]    [Pg.230]    [Pg.9]    [Pg.446]   
See also in sourсe #XX -- [ Pg.222 ]

See also in sourсe #XX -- [ Pg.222 ]

See also in sourсe #XX -- [ Pg.222 ]

See also in sourсe #XX -- [ Pg.97 , Pg.222 ]



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Heterocumulene

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Reaction with Heterocumulene Derivatives

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