| ²é¿´: 319 | »Ø¸´: 2 | |||
| µ±Ç°Ö÷ÌâÒѾ´æµµ¡£ | |||
ɳ½¨Í¤Ìú³æ (³õÈëÎÄ̳)
|
[½»Á÷]
·Òë---Óлú·½ÃæµÄ
|
||
|
The relative rates of reaction of sodium enolate of diethyl n-butyl malonate with n-butyl btomide are shown in table1.3 Dimethyl sulfoxide (DMSO) and N,N-dimeth ylformamide (DMF) are particularly effective in enhancing the reactivity of enolate ions. Both of these are polar aprotic solvents. Other compounds that are used as cosolvents in reactions between enolates and alkyl halides include N-methylpyrrolidone (NMP), hexamethylphosphoric triamide (HMPA) and N,N-dimethylpropyleneurea (DMPU).42Polar aprotic solvents, as the name indicates, are materials that have high dielectric constants but lack hydroxy or other hydrogen- bonding groups. Polar aprotic solvents possess excellent metal cation coordination ability, so they can solvate and dissociate enolates and other carbanions from ion pairs and clusters. |
» ²ÂÄãϲ»¶
312Çóµ÷¼Á
ÒѾÓÐ15È˻ظ´
304Çóµ÷¼Á
ÒѾÓÐ7È˻ظ´
»¯¹¤Çóµ÷¼Á£¡
ÒѾÓÐ15È˻ظ´
284Çóµ÷¼Á
ÒѾÓÐ8È˻ظ´
362Çóµ÷¼Á
ÒѾÓÐ5È˻ظ´
Ò»Ö¾Ô¸¹þ¹¤´ó£¬³õÊÔ329£¬Çó»·¾³¿ÆÑ§Ó빤³Ìµ÷¼Á£¡
ÒѾÓÐ5È˻ظ´
327Çóµ÷¼Á
ÒѾÓÐ3È˻ظ´
Ò»Ö¾Ô¸¼ª´ó»¯Ñ§327Çóµ÷¼Á
ÒѾÓÐ5È˻ظ´
26×ÔÈ»µØÀíѧ303·ÖÇóµ÷¼Á
ÒѾÓÐ8È˻ظ´
336Çóµ÷¼Á£¬Ò»Ö¾Ô¸Öпƴó
ÒѾÓÐ4È˻ظ´
zhongren12345
ÖÁ×ðľ³æ (ÖøÃûдÊÖ)
- Ó¦Öú: 0 (Ó×¶ùÔ°)
- ½ð±Ò: 30338.4
- É¢½ð: 102
- Ìû×Ó: 2861
- ÔÚÏß: 126.2Сʱ
- ³æºÅ: 440344
- ×¢²á: 2007-10-27
- ÐÔ±ð: GG
- רҵ: ÓлúºÏ³É
|
¶þ¶¡»ù±û¶þÏ©´¼ÄÆÓëN - ±û¶þÕý¶¡õ¥btomideÏà¶ÔÀûÂʵķ´Ó¦ÁÐÓÚ±í1.3.¶þ¼×»ùÑÇí¿£¨¶þ¼×»ùÑÇí¿£©ºÍN £¬ N -¶þ¼×»ù¼×õ£°·£¨ DMF¶¯£©ÌرðÓÐЧÌá¸ß·´Ó¦Ï©´¼Àë×Ó¡£ÕâЩ¶¼ÊǼ«ÐÔ·ÇÖÊ×ÓÈܼÁ¡£ÆäËû»¯ºÏÎï±»ÓÃ×÷ÈܼÁÖз´Ó¦enolatesºÍ±´úÌþ°üÀ¨NÒ»¼×»ù£¨µ°°×ø£© £¬ examethylphosphoricÈý°·£¨ HMPA £©ºÍN £¬ N - imethylpropyleneurea £¨ DMPU £© 0.42ÖÊ×Ó¼«ÐÔÈܼÁ£¬ÈçÃû³ÆËùʾ£¬ÓвÄÁÏ£¬Óи߽éµç³£Êý£¬µ«È±·¦ôÇ»ù»òÆäËûÇâ¼üµÄȺÌå¡£¼«ÐÔ·ÇÖÊ×ÓÈܼÁÖоßÓÐÁ¼ºÃµÄ½ðÊôÑôÀë×Óе÷ÄÜÁ¦£¬Ê¹ËûÃÇÄܹ»ÈܼÁºÍÓÎÀëenolatesºÍÆäËû̼¸ºÀë×ÓµÄÀë×ӶԺͼ¯Èº¡£ ±¾ÈËרҵӢÎÄÒ²ÊÇ¸Õ¸ÕÆð²½£¬Ï£ÍûÄÜÓÐËù°ïÖú£¡ |
2Â¥2008-12-04 14:36:21
yunlovers
ͳæ (ÕýʽдÊÖ)
- Ó¦Öú: 0 (Ó×¶ùÔ°)
- ½ð±Ò: 131.9
- É¢½ð: 2
- Ìû×Ó: 423
- ÔÚÏß: 17.7Сʱ
- ³æºÅ: 614924
- ×¢²á: 2008-09-28
- ÐÔ±ð: MM
- רҵ: É«Æ×·ÖÎö
|
2-Õý¶¡õ£»ù±û¶þËá¶þÒÒõ¥µÄÏ©´¼Ê½ÄÆÑκÍÕý¶¡õ£»ùäå·´Ó¦µÄÏà¶Ô±ÈÔÚ±í1.3ÖÐÁгö¡£¶þ¼×»ùÑÇí¿£¨DMSO£©ºÍN £¬ N -¶þ¼×»ù¼×õ£°·(DMF)Äܹ»ÏÔÖøµØÔöǿϩ´¼Ê½Ñεķ´Ó¦ÐÔ¡£¶þÕß¾ùΪ¼«ÐÔ·ÇÖÊ×ÓÐÔÈܼÁ¡£Ï©´¼Ê½ÑκͱÌþÀ෴Ӧʱ³£¼ÓÈëһЩDZÈܼÁÎïÖÊ£¬ÈçN-¼×»ùßÁ¿©Íéͪ£¬Áù¼×»ùÁ×ËáÈýõ£°·£¨HMPA£©£¬N,N-¶þ¼×»ù±ûÏ©»ùë壨 DMPU £© ¼«ÐÔ·ÇÖÊ×ÓÐÔÈܼÁ£¬ÕýÈçÃû×ÖËùÏÔʾµÄ£¬º¬ÓиߵĽéµç³£Êý£¬µ«ÊÇȱ·¦ôÇ»ù»òÕß½áºÏÇâµÄ»ùÍÅ¡£¼«ÐÔ·ÇÖÊ×ÓÐÔÈܼÁÄܹ»ºÜºÃµÄÓë½ðÊôÑôÀë×ÓÅä룬Òò´Ë£¬ÕâЩÈܼÁÄܹ»ºÜºÃµÄÈܽâºÍ·ÖÀëÏ©´¼Ê½ÑΣ¬ÒÔ¼°±ðµÄ̼¸ºÀë×ÓµÄÀë×Ó¶ÔºÍÀë×ÓȺ¡£ |

3Â¥2008-12-04 19:37:26














»Ø¸´´ËÂ¥