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With the formula (HO) 2 P(O)CH 2 NHCH 2 CO 2 H, this derivative of glycine is one of the most widely used herbicides. Bisphosphonates are a class of drugs to treat osteoporosis. The nerve gas agent sarin, containing both C–P and F–P bonds, is a phosphonate. [citation needed] Phosphinates feature two P–C bonds, with the general formula R 2 ...
P-persistent This approach lies between the 1-persistent and non-persistent CSMA access modes. [1] When the transmitting node is ready to transmit data, it senses the transmission medium for idle or busy. If idle, then it transmits immediately. If busy, then it senses the transmission medium continuously until it becomes idle, then transmits ...
Phosphorimidazolides have been investigated for their mechanistic role in abiogenesis (the natural process by which life arose from non-living matter). Specifically, they have been proposed as the active electrophilic species which may have mediated the formation of inter-nucleotide phosphodiester bonds, thereby enabling template-directed oligonucleotide replication before the advent of enzymes.
[1] [2] It belongs to the larger class of conjugate additions and is widely used for the mild formation of carbon-carbon bonds. [3] The Michael addition is an important atom-economical method for diastereoselective and enantioselective C–C bond formation, and many asymmetric variants exist [4] [5] [6]
Sterically bulky phospholkyne (Mes*C≡P) is treated with 0.5 equiv of t-BuLi in THF to form a 1,3 diphosphaalkyl anion. This is reduced with iodine solution to form a red product. The species is a planar four-membered diphosphacyclobutane (C 2 P 2) ring with the Mes* having torsional angles with the C 2 P 2 plane. [8]
1,3-Dimesityl-imidazol-4,5-dihydro-2-ylidene, a representative persistent carbene. A persistent carbene (also known as stable carbene) is an organic molecule whose natural resonance structure has a carbon atom with incomplete octet (a carbene), but does not exhibit the tremendous instability typically associated with such moieties.
The figure below illustrates one of the commonly accepted models for stereoselection without any modification to the Henry reaction. In this model, stereoselectivity is governed by the size of the R groups in the model (such as a carbon chain), as well as by a transition state that minimizes dipole by orienting the nitro group and carbonyl oxygen anti each other (on opposite sides of the ...
In one important reaction type, a main group organometallic compound of the type R-M (where R = organic group, M = main group centre metal atom) reacts with an organic halide of the type R'-X with formation of a new carbon-carbon bond in the product R-R'. The most common type of coupling reaction is the cross coupling reaction. [1] [2] [3]