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In nature, methoxy groups are found on nucleosides that have been subjected to 2′-O-methylation, for example in variations of the 5′-cap structure known as cap-1 and cap-2. They are also common substituents in O -methylated flavonoids , whose formation is catalyzed by O-methyltransferases that act on phenols , such as catechol- O -methyl ...
Trimethyl borate is the organoboron compound with the formula B(OCH 3) 3 and a metal alkoxide. It is a colourless liquid that burns with a green flame. [1] It is an intermediate in the preparation of sodium borohydride and is a popular reagent in organic chemistry. It is a weak Lewis acid (AN = 23, Gutmann-Beckett method). [2]
Cyclooctadiene iridium methoxide dimer is an organoiridium compound with the formula Ir 2 (OCH 3) 2 (C 8 H 12) 2, where C 8 H 12 is the diene 1,5-cyclooctadiene. It is a yellow solid that is soluble in organic solvents. The complex is used as a precursor to other iridium complexes, some of which are used in homogeneous catalysis. [1]
P(OCH 3) 3 → CH 3 P(O)(OCH 3) 2. As a ligand, trimethyl phosphite has a smaller cone angle and better acceptor properties relative to trimethylphosphine. A representative derivative is the colorless tetrahedral complex Ni(P(OMe) 3) 4 (m.p. 108 °C). [4] The tridentate ligand called the Kläui ligand is derived from trimethyl phosphite. The ...
Let (X, O) be a ringed space.If F and G are O-modules, then their tensor product, denoted by . or ,. is the O-module that is the sheaf associated to the presheaf () (). (To see that sheafification cannot be avoided, compute the global sections of () = where O(1) is Serre's twisting sheaf on a projective space.)
L −2 M −1 T 3 I 2: scalar Electrical conductivity: σ: Measure of a material's ability to conduct an electric current S/m L −3 M −1 T 3 I 2: scalar Electric potential: φ: Energy required to move a unit charge through an electric field from a reference point volt (V = J/C) L 2 M T −3 I −1: extensive, scalar Electrical resistance: R
In combinatorics, the twelvefold way is a systematic classification of 12 related enumerative problems concerning two finite sets, which include the classical problems of counting permutations, combinations, multisets, and partitions either of a set or of a number.
The sum is taken over all combinations of nonnegative integer indices k 1 through k m such that the sum of all k i is n. That is, for each term in the expansion, the exponents of the x i must add up to n. [1] [a] In the case m = 2, this statement reduces to that of the binomial theorem. [1]