Bulky R group

If the thiazole under consideration reacts in its neutral form, the ring nitrogen is expected to be reactive center. Exceptions could be expected for 2-araino-4-R thiazoies with bulky R groups and for electrophilic reactants able to generate a carbocation. 

Phthalocyanine-based dyes are especially useful for CD-R, as the chromophore absorption band falls in the desirable spectral range, and they are noted for excellent photostability. Unlike cyanine dyes, phthalocyanines tend to have very poor solubility, particularly in solvents such as alcohols and aliphatic hydrocarbons (which do not attack polycarbonate and are therefore used for spin coating). Therefore, the main barrier to the wider use of these dyes is the relatively high cost of synthesizing soluble derivatives. Suitable modifications to the Pc core which have been developed, notably by Mitsui Toatsu, are shown in Scheme 7. The bulky R groups reduce undesirable molecular association (which in turn lower the extinction coefficient and hence reflectivity), whereas partial bromination allows fine-tuning of the film absorbance and reflectivity. The metal atom influences the position of the absorption band, the photostability, and the efficiency of the radiationless transition from the excited state.199 This material is marketed by Ciba as Supergreen.204... 

The value of the Pi parameter for an isocyanide ligand (without a bulky R group) can then be used to predict whether the coordination mode is bent or Knear, that is, with a dominant representation by form a or b, respectively. 

A bulky R group in 93 makes the s-trans/s-cis ratio more dependent (71CC1209 76JCS(P2)761) on R, while energy barriers are close (7ICC1209) to those found in the A-acylprolines not esterified. 

A ketone with two bulky R groups, e.g., —C(CH,), would be too sterically hindered to react with an organometallic compound with a bulky R group. 

H-bonds. The a C s rotate slightly out of the plane of the merger (to minimize repulsions between their bulky R groups), which gives rise to the pleats. ... 

Benzodiazepin-4-ones (315) have been synthesized by the Cu20-catalyzed cyclization of (314) the competing route to indoles is disfavored by bulky R groups (79TL1039). 

The ability of the cations [M(CNR)4]+ (M = Rh, Ir) to self-associate is a function of steric crowding in the molecule, and for bulky R groups monomeric species predominate. An estimate has been made of the steric size of isocyanides in terms of fan-shaped angles and as part of this study the structure of RhCl(CNC6H2Bu -2,4,6)3 has been elucidated (126). The structural determinations of a series of dimeric rhodium(I) isocyanide salts have been completed. An eclipsed configuration was found for [Rh2 CN (CH2)3NC)4](BPh4)2 NCMe (42)2 (287), whereas [Rh2(CNPh)8]-... 

Substantial amounts of anti-Markovnikov products have been found for bromination of non-symmetrically substituted olefins RCH=CH2 in methanol, particularly with bulky R groups (R = Bib and Pr1)109. Mechanistic studies of a novel regiospecific hydroxy-bromination, employing CBr4, 02 and RO (R = Me, Pr1, Bu ) as reagents, suggest that both radical and carbanionic intermediates are involved180. 

Presumably PPh molecules are formed, but these do not stop at mere dimerisation. A molecule RP=PR will presumably have as its most stable geometrical isomer the trans form, especially with bulky R groups ... 

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