Gilman 1,4-addition

In addition to those methods already discussed, ketones can also be prepared from certain carboxylic acid derivatives, just as aldehydes can. Among the most useful reactions of this type is that between an acid chloride and a Gilman diorganocopper reagent such as we saw in Section 10.8. We ll discuss this subject in more detail in Section 21.4. 

Coniine, molecular model of. 28 structure of, 294 Conjugate acid, 49 Conjugate base, 49 Conjugate carbonyl addition reaction, 725-729 amines and, 727 enamines and, 897-898 Gilman reagents and, 728-729 mechanism of, 725-726 Michael reactions and, 894-895 water and. 727 Conjugated diene, 482... 

Since the preformed aggregate Bu3Cu2Li showed a diastereoselectivity of 83 17 in the presence of boron trifluoride16, the low diastereoselectivity noted above was presumably due to a faster addition reaction of butyllithium, which is formed by the treatment of the Gilman cuprate with the boron trifluoride-diethyl ether complex16,, s. 

Although this sometimes occurs through the operation of Frank-Read sources it is not generally observed. What does generally occur is similar, but more complex. The process is called multiple-cross-glide, and was proposed by Koehler (1952). Its importance was hrst demonstrated experimentally by Johnston and Gilman (1959). In addition to its existence, they showed that the process produces copious dislocation dipoles which are responsible for deformation-hardening. 

Chin, et al. (1972) measured the hardnesses of Na and K halides (Cl, Br, and I) containing various additions of Ca++, Sr++, or Ba++. Then they extrapolated the measurements back to zero additions to get values for the pure crystals. They found that the latter depended linearly on the Young s moduli of their crystals. Gilman (1973) found an equally good correlation with the shear stiffnesses, where FI = 1.37 x 10 2 C44 (d/cm2) in excellent agreement with Equation 9.1. A comparison of the data and the theory is given in Figure 9.5. 

Since then, several different alkali metal silanide systems have been reported. One of them, the hypersilyl [Si(SiMe3)3] ligand, was first prepared by Gilman and Smith.172, 173 Another ligand includes supersilyl [SPBuJ-prepared in 1975.174-176 Several other variations of the ligand systems are known with the recent addition of [SkB Ph]-, for which several alkali metal derivatives have been prepared and characterized.177,178... 

The family of heterotrimeric G proteins is involved in transmembrane signaling in the nervous system, with certain exceptions. The exceptions are instances of synaptic transmission mediated via receptors that contain intrinsic enzymatic activity, such as tyrosine kinase or guanylyl cyclase, or via receptors that form ion channels (see Ch. 10). Heterotrimeric G proteins were first identified, named and characterized by Alfred Gilman, Martin Rodbell and others close to 20 years ago. They consist of three distinct subunits, a, (3 and y. These proteins couple the activation of diverse types of plasmalemma receptor to a variety of intracellular processes. In fact, most types of neurotransmitter and peptide hormone receptor, as well as many cytokine and chemokine receptors, fall into a superfamily of structurally related molecules, termed G-protein-coupled receptors. These receptors are named for the role of G proteins in mediating the varied biological effects of the receptors (see Ch. 10). Consequently, numerous effector proteins are influenced by these heterotrimeric G proteins ion channels adenylyl cyclase phosphodiesterase (PDE) phosphoinositide-specific phospholipase C (PI-PLC), which catalyzes the hydrolysis of phosphatidylinositol 4,5-bisphosphate (PIP2) and phospholipase A2 (PLA2), which catalyzes the hydrolysis of membrane phospholipids to yield arachidonic acid. In addition, these G proteins have been implicated in... 

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