The Analogy between O and C(CN)₂

Abstract

The compounds of oxygen, i. e. OH acids, ethers, quinones, aldehydes, ketones, carboxylic esters and amine oxides, sulfoxides, and phosphane oxides, are compared and contrasted with those compounds which contain a C(CN), moiety in place of the characteristic 0 atom. In their typical properties the .pairs of analogs frequently display surprising agreement. The purpose of such analogy studies lies primarily in the estimation of reactivities; their limits are reached where specific properties of the structural components become effective.

High-Yield, Automated Radiosynthesis of 2-(1-{6-[(2-[18F]Fluoroethyl)(methyl)amino]-2-naphthyl}ethylidene)malononitrile ([18F]FDDNP) Ready for Animal or Human Administration

“…In fact, the radiochemical yield of [ 18 F]FENE did not exceed 11%, even with prolonged heating and with little [ 18 F]FDDNP remaining in the basic reaction mixture (Table 2, entry 10). In addition to the possible reaction of naphthyl ketones in basic solution [32], the ethylidenemalononitrile moiety in [ 18 F]FDDNP, due to the extreme polarity of the double bond, may suffer dimerization [33,34]. Therefore, removing the base from the reaction mixture by using acid prevented these secondary reactions from happening during isolation and purification, thereby increasing the reproducibility of the synthesis.…”

Solution photochemistry of 4-alkylidene-3,3,5,5-tetramethyl-Δ1-pyrazolines

“…It gives mainly the ' least motions ' product ( [2H6] isopropylidene) -2,2,3,3tetramethylcyclopropane (1 2). This implies that the sing/et TMM adopts a bis-orthogonal geometry (21 ) rather than the mono-orthogonal geometry (20) expected. Direct photolysis of 13 different a-methylated 4-alkylidenepyrazolines (5) shows that, in this series, formation of the ' least motions ' product (22) is normally preferred.…”

Enzyme Chemistry

“…Similarly, Shinkai and Kunitake (1977) noticed that the aldehyde group in (3.17) is readily reduced .4 Ternary complex of lactate dehydrogenase based on an X-ray crystallographic study (Adams et al, 1973). by (3.1) with the aid of the intramolecular imidazole function. It is also known that the addition of trace amounts of proton acids facilitates NADH model reductions (Shinkai and Kunitake, 1977;Wallenfels et al, 1973). Van Eikeren and Grier (1976) found that the reduction rate of tri-fluoroacetophenone by (3.1: R = n-Pr) is markedly facilitated in protic solvents rather than in aprotic solvents.…”

“…Wallenfels and Hanstein (1965) showed that 9fluorenol is oxidized to fluorenone (8% yield) by (3.48). In contrast to a great number of investigations on the NADH model reduction of carbonyl substrates, there are few examples ofthe NAD+ model oxidation of alcohol substrates.…”