EFFECT OF PRECURSOR STRUCTURES ON ARYLCARBENE PROCESSES IN LOW-TEMPERATURE MATRICES - IMPORTANCE OF TOPOCHEMICALLY CONTROLLED PROCESSES

被引:46
作者
TOMIOKA, H [1 ]
GRIFFIN, GW [1 ]
NISHIYAMA, K [1 ]
机构
[1] UNIV NEW ORLEANS,DEPT CHEM,NEW ORLEANS,LA 70122
关键词
D O I
10.1021/ja00514a023
中图分类号
O6 [化学];
学科分类号
0703 ;
摘要
C-H insertion selectivities of [PhCH:] generated from diverse sources, i.e., PhCHN2 and cis-and trans-2,3-diphenyloxiranes, in 2-propanol and 2,3-dimethylbutane matrices at -196 °C showed considerable dependence on the structure of precursors, while liquid-phase experiments showed that insertion selectivities were essentially invariant regardless of source. [Ph2C:] generated from Ph2CN2, tetraphenyloxirane, and 2,2,4,4-tetraphenyloxetan-3-one showed precursor dependences of C-H insertion selectivities as well as singlet/triplet product ratio even in the liquid phase and more dramatically in the solid phase. Possible effects of precursors on the angle and energy of nascent carbene and sensitization by photofragment (Ph2CO) were excluded based on control experiments and EPR studies. Topochemical factors, i.e., contact of carbene center with the host molecules, are considered to play an important role especially in the matrix reactions and hence it has been suggested that attempts to extrapolate singlet/triplet carbene ratios from product compositions in matrices could prove unreliable since the fate of carbenes generated in a matrix may be predestined by site preference imposed upon the precursor. © 1979, American Chemical Society. All rights reserved.
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页码:6009 / 6012
页数:4
相关论文
共 32 条
[11]   NEW PRECURSORS FOR ARYLCARBENES - PHOTOCYCLOELIMINATION REACTIONS OF CYCLIC SULFITES [J].
GRIFFIN, GW ;
MANMADE, A .
JOURNAL OF ORGANIC CHEMISTRY, 1972, 37 (16) :2589-&
[12]  
GRIFFIN GW, 1960, TETRAHEDRON LETT, P13
[13]   NEW PRECURSORS FOR ARYLCARBENES - PHOTOCYCLOELIMINATION REACTIONS OF CYCLIC CARBONATES [J].
GRIFFIN, GW ;
SMITH, RL ;
MANMADE, A .
JOURNAL OF ORGANIC CHEMISTRY, 1976, 41 (02) :338-345
[14]  
GRIFFIN GW, 1973, CARBENES, V1, P305
[15]   ELECTRON-PARAMAGNETIC RESONANCE-SPECTRA OF CARBALKOXYCARBENES - GEOMETRIC ISOMERISM IN GROUND-STATE TRIPLETS [J].
HUTTON, RS ;
ROTH, HD .
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY, 1978, 100 (13) :4324-4325
[16]   CARBENE-CARBENE REARRANGEMENTS [J].
JONES, WM ;
JOINES, RC ;
MYERS, JA ;
MITSUHAS.T ;
KRAJCA, KE ;
WAALI, EE ;
DAVIS, TL ;
TURNER, AB .
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY, 1973, 95 (03) :826-835
[17]   INSERTION REACTIONS OF 4H-IMIDAZOLYLIDENES INTO C-H BONDS OF ALCOHOLS [J].
KANG, UG ;
SHECHTER, H .
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY, 1978, 100 (02) :651-652
[18]   PHOTOLYSIS OF PHENYLDIAZOMETHANE IN OLEFINIC MATRICES - CHEMISTRY OF TRIPLET PHENYLCARBENE [J].
MOSS, RA ;
DOLLING, UH .
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY, 1971, 93 (04) :954-&
[19]   REACTIONS OF CARBENES AT LOW-TEMPERATURES - DIPHENYLCARBENE AND ISOBUTENE [J].
MOSS, RA ;
HUSELTON, JK .
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY, 1978, 100 (04) :1314-1315
[20]   REACTIONS OF METHYLPHENYLCARBENE AND PHENYLCARBENE IN ISOBUTENE MATRICES - ORIGINS OF INSERTION PRODUCTS [J].
MOSS, RA ;
JOYCE, MA .
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY, 1977, 99 (04) :1262-1264