Electronic and steric effects on the intramolecular Schmidt reaction of alkyl azides with secondary benzyl alcohols

Boron trimethyl reacts with each of the organometalloid-hydrazine derivatives Me2NN(R)GeMe3 (R = H, Me, SiMe3) except Me2NN(SiMe3)GeMe3, and with Me2NNHSiMe3, forming 1:1 adducts. With Me2NN(SiMe3)GeMe3 and BMe3, no adduct was formed even at low temperatures. On the basis of p.m.r. spectra, the metalloid-substituted nitrogen atom rather than the terminal nitrogen, is indicated as the basic center at which adduct formation occurs. With BF3, the Si—N and Ge—N bonds of the hydrazine derivatives were cleaved, again indicating attack at the central nitrogen atom. In a series of experiments involving CY2 (Y = O, S) and Me2NN(R)MMe3 (R = H, Me, SiMe3; M = Si, Ge), reaction occurred readily for R = H, but less readily for R = Me and for the compound Me2NN(GeMe3)2, while no reaction was observed for the compounds Me2NN(SiMe3)2 and Me2NN(SiMe3)GeMe3, even when heat or basic catalysts were employed. Reaction products, carbamate and thiocarbamate derivatives, Me2NN(R)C(Y)YMMe3, were characterized on the basis molecular weight, i.r., p.m.r., and mass spectroscopy, and m.p. data. Ease of formation is discussed in terms of electronic and steric effects.

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Highly Stereo- and Regioselective Allylations Catalyzed by Mo−Pyridylamide Complexes: Electronic and Steric Effects of the Ligand

The Journal of Organic Chemistry ◽

10.1021/jo0006829 ◽

2000 ◽

Vol 65 (18) ◽

pp. 5868-5870 ◽

Cited By ~ 46

Author(s):

Oscar Belda ◽

Nils-Fredrik Kaiser ◽

Ulf Bremberg ◽

Mats Larhed ◽

Anders Hallberg ◽

...

Keyword(s):

Steric Effects ◽

Electronic And Steric Effects

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Prediction of retention indices. VI: Isothermal and temperature-programmed retention indices, methylene value, functionality constant, electronic and steric effects

Journal of Chromatography A ◽

10.1016/j.chroma.2010.02.005 ◽

2010 ◽

Vol 1217 (23) ◽

pp. 3683-3694 ◽

Cited By ~ 9

Author(s):

C.T. Peng

Keyword(s):

Retention Indices ◽

Steric Effects ◽

Prediction Of Retention ◽

Temperature Programmed ◽

Electronic And Steric Effects

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Study of naphthopyran derivatives: structure and photochromic properties in solution and in polymer film

Acta Crystallographica Section C Structural Chemistry ◽

10.1107/s2053229621005969 ◽

2021 ◽

Vol 77 (7) ◽

Author(s):

Linqi Shi ◽

Zipei Sun ◽

Jiajie Tian ◽

Yaodong Huang ◽

Jiben Meng

Keyword(s):

Uv Light ◽

Steric Effects ◽

Pmma Film ◽

Structure Property ◽

Photochromic Properties ◽

X Ray ◽

Structure Property Relationships ◽

Substituent Group ◽

Uv Light Irradiation ◽

Electronic And Steric Effects

Four naphthopyran derivatives, namely, 3,3-bis(naphthalen-1-yl)-3H-naphtho[2,1-b]pyran, C33H22O, NP1, 3,3-bis([1,1′-biphenyl]-4-yl)-3H-naphtho[2,1-b]pyran, C37H26O, NP2, 3,3-bis(4-phenoxyphenyl)-3H-naphtho[2,1-b]pyran, C37H26O2, NP3, and 3,3-bis(4-methoxy-2-methylphenyl)-3H-naphtho[2,1-b]pyran, C29H26O3, NP4, were synthesized and their photochromic properties investigated. NP1–NP4 exhibited good photochromism in different solutions and in poly(methyl methacrylate) (PMMA) film under UV light irradiation. Solvatochromism and the electronic and steric effects of the substituent group on photochromism were analyzed and decolouration curves were found to fit a monoexponential kinetic decay in most cases. Single-crystal X-ray analysis of NP1 and NP2 revealed the structure–property relationships. Good fatigue resistance of NP1, both in solution and in the PMMA film, endows it with potential value for applications.

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