1-Titanacyclobuta-2,3-diene – an elusive four-membered cyclic allene
نویسندگان
چکیده
منابع مشابه
Tetrahydroxy 10-membered cyclic enediynes.
The preparation of cyclic 10-membered tetrahydroxy enediynes is reported. The synthesis starts from tartaric acid and allows the control of the relative stereochemistry. Acetal protection of the 2,3-hydroxy groups stabilizes the enediyne during synthesis. Removal of the cyclic protecting group with EtSH/TFA transforms the stable compounds into reactive enediynes, and the rate constants of their...
متن کاملStable four-pi-electron, four-membered heterocyclic cations and carbenes.
Replacement of halide from N-(haloboryl)formamidines for the weakly coordinating anion [B(C(6)F(5))(4)](-), using [Et(3)Si(toluene)](+)[B(C(6)F(5))(4)](-), induces a ring closure leading to the cationic four-pi-electron four-membered heterocycles [HC(N-2,6-diisopropylphenyl)(2)BR](+) [R = N(i-Pr)(2), Ph]. Subsequent deprotonation of the B-amino derivative affords the corresponding N-heterocycli...
متن کاملA stable four-membered N-heterocyclic carbene.
The synthesis of the first four-membered N-heterocyclic carbene is described. Depending on the substituents on the nitrogen atoms, it is possible to characterize at room temperature the carbene dimer or the free carbene. Crystallographic analyses are provided for these carbene species.
متن کاملAb Initio Study of Conformational and Configurational Properties of 1, 3- Diazacyclohepta-1, 2-diene and 1, 3-Diazacycloocta-1, 2-diene
Ab initio calculations at HF/6-31G* level of theory for geometry optimization and MP2/6-31G*//HF/6-31G* for a single point total energy calculation are reported for the importantenergy-minimum conformations and transition-state geometries of 1, 3-diazacyclohepta-1, 2-diene (2) and 1, 3-diazacycloocta-1, 2-diene (3). The C2 symmetric twist-chair (2-TC)conformation of 2 is calculated to be 7.4 kJ...
متن کاملA [4 + 4] annulation strategy for the synthesis of eight-membered carbocycles based on intramolecular cycloadditions of conjugated enynes.
A [4 + 4] annulation strategy for the synthesis of eight-membered carbocycles is reported that proceeds via a cascade involving two pericyclic processes. In the first step, the [4 + 2] cycloaddition of a conjugated enyne with an electron-deficient cyclobutene generates a strained six-membered cyclic allene that isomerizes to the corresponding 1,3-cyclohexadiene. In the second step, this bicyclo...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: Chemical Science
سال: 2019
ISSN: 2041-6520,2041-6539
DOI: 10.1039/c9sc01002e