249:
263:
277:
20:
399:
1318:
1323:
365:
338:
392:
1222:
1346:
795:
385:
214:
groups) are sometimes called active methylene compounds. Treatment of these with strong bases can form
199:
832:
227:
1305:
231:
1205:
1312:
1200:
86:
1281:
726:
152:
8:
587:
136:). As a bridge in other compounds, for example in cyclic compounds, it is given the name
354:
248:
98:
276:
262:
1271:
1241:
999:
621:
361:
223:
141:
28:
976:
408:
1195:
954:
949:
932:
915:
716:
465:
300:
145:
113:
19:
1266:
1261:
1137:
1132:
1127:
920:
887:
671:
653:
643:
203:
68:
1340:
1286:
1234:
1165:
1051:
1041:
1036:
1026:
1021:
971:
966:
882:
877:
867:
721:
676:
638:
626:
597:
475:
282:
268:
1217:
1104:
1099:
1076:
827:
666:
592:
529:
524:
502:
458:
443:
433:
295:
254:
1276:
1229:
1190:
1071:
959:
944:
939:
927:
492:
487:
453:
448:
438:
416:
168:
64:
178:), giving it chemical properties very distinct from those of a bridging
1185:
1176:
1056:
1011:
907:
872:
862:
802:
738:
661:
609:
219:
1152:
1066:
1031:
1016:
1004:
847:
822:
631:
79:
377:
67:
to two other distinct atoms in the rest of the molecule. It is the
1160:
1114:
1081:
777:
683:
557:
512:
497:
215:
207:
198:
Compounds possessing a methylene bridge located between two strong
94:
90:
60:
44:
1122:
1046:
897:
892:
857:
842:
837:
807:
790:
614:
541:
507:
305:
211:
149:
1210:
1142:
986:
695:
688:
582:
563:
552:
536:
482:
242:
Examples of compounds which contain methylene bridges include:
82:
72:
56:
1091:
1061:
994:
852:
817:
812:
785:
733:
700:
604:
428:
167:
group when it is connected to the rest of the molecule by a
519:
16:
Any part of a molecule with the chemical formula –CH2–
324:W. A. Herrmann (1982), "The methylene bridge". In
353:
1338:
393:
400:
386:
23:The methylene bridge (methanediyl group)
18:
318:
1339:
407:
381:
351:
104:A methylene bridge is often called a
78:A methylene bridge can also act as a
326:Advances in Organometallic Chemistry
360:. Menlo Park, CA.: W. A. Benjamin.
13:
144:(not to be confused with the term
71:in the skeleton of the unbranched
14:
1358:
275:
261:
247:
345:
331:
112:, as in "methylene chloride" (
1:
311:
193:
7:
339:"Active methylene compound"
328:, volume 20, pages 195-197.
289:
237:
200:electron withdrawing groups
10:
1363:
356:Modern Synthetic Reactions
352:House, Herbert O. (1972).
222:, which are often used in
155:) properly applies to the
1295:
1254:
1174:
1151:
1113:
1090:
985:
906:
776:
753:
709:
652:
575:
550:
415:
228:Knoevenagel condensation
85:joining two metals in a
1306:chemical classification
232:malonic ester synthesis
226:. Examples include the
63:atoms and connected by
24:
1313:chemical nomenclature
87:coordination compound
22:
140:. However, the term
769:not C, H or O)
1211:Hypervalent iodine
59:atom bound to two
25:
1347:Functional groups
1334:
1333:
1272:Sulfenyl chloride
1250:
1249:
749:
748:
568:(only C, H and O)
409:Functional groups
224:organic synthesis
142:methylidene group
43:is any part of a
41:methanediyl group
29:organic chemistry
1354:
1301:
1206:Trifluoromethoxy
774:
773:
770:
573:
572:
569:
422:
402:
395:
388:
379:
378:
372:
371:
359:
349:
343:
342:
335:
329:
322:
279:
265:
251:
189:
188:
187:
177:
166:
165:
164:
135:
134:
133:
125:
124:
54:
37:methylene spacer
33:methylene bridge
1362:
1361:
1357:
1356:
1355:
1353:
1352:
1351:
1337:
1336:
1335:
1330:
1299:
1291:
1246:
1201:Trichloromethyl
1196:Trifluoromethyl
1170:
1147:
1109:
1086:
981:
950:Phosphine oxide
902:
768:
766:
765:
763:
761:
759:
757:
755:
745:
705:
648:
567:
566:
561:
556:
546:
420:
419:
411:
406:
376:
375:
368:
350:
346:
337:
336:
332:
323:
319:
314:
301:Methylene group
292:
285:
280:
271:
266:
257:
252:
240:
196:
186:
183:
182:
181:
179:
176:
172:
163:
160:
159:
158:
156:
146:methylene group
132:
129:
128:
127:
123:
120:
119:
118:
116:
114:dichloromethane
106:methylene group
99:Tebbe's reagent
52:
48:
17:
12:
11:
5:
1360:
1350:
1349:
1332:
1331:
1329:
1328:
1327:
1326:
1321:
1309:
1302:
1296:
1293:
1292:
1290:
1289:
1287:Sulfinylamines
1284:
1279:
1274:
1269:
1267:Phosphoramides
1264:
1262:Isothiocyanate
1258:
1256:
1252:
1251:
1248:
1247:
1245:
1244:
1239:
1238:
1237:
1227:
1226:
1225:
1215:
1214:
1213:
1208:
1203:
1198:
1193:
1182:
1180:
1172:
1171:
1169:
1168:
1163:
1157:
1155:
1149:
1148:
1146:
1145:
1140:
1138:Selenenic acid
1135:
1133:Seleninic acid
1130:
1128:Selenonic acid
1125:
1119:
1117:
1111:
1110:
1108:
1107:
1102:
1096:
1094:
1088:
1087:
1085:
1084:
1079:
1074:
1069:
1064:
1059:
1054:
1049:
1044:
1039:
1034:
1029:
1024:
1019:
1014:
1009:
1008:
1007:
997:
991:
989:
983:
982:
980:
979:
974:
969:
964:
963:
962:
952:
947:
942:
937:
936:
935:
925:
924:
923:
921:Phosphodiester
912:
910:
904:
903:
901:
900:
895:
890:
885:
880:
875:
870:
865:
860:
855:
850:
845:
840:
835:
830:
825:
820:
815:
810:
805:
800:
799:
798:
793:
782:
780:
771:
767:(one element,
751:
750:
747:
746:
744:
743:
742:
741:
731:
730:
729:
724:
713:
711:
707:
706:
704:
703:
698:
693:
692:
691:
681:
680:
679:
674:
669:
658:
656:
650:
649:
647:
646:
644:Methylenedioxy
641:
636:
635:
634:
629:
619:
618:
617:
612:
602:
601:
600:
590:
585:
579:
577:
570:
548:
547:
545:
544:
539:
534:
533:
532:
527:
517:
516:
515:
510:
505:
500:
495:
490:
480:
479:
478:
473:
463:
462:
461:
456:
451:
446:
441:
436:
425:
423:
421:(only C and H)
413:
412:
405:
404:
397:
390:
382:
374:
373:
366:
344:
330:
316:
315:
313:
310:
309:
308:
303:
298:
291:
288:
287:
286:
281:
274:
272:
267:
260:
258:
253:
246:
239:
236:
195:
192:
184:
174:
161:
130:
121:
69:repeating unit
50:
15:
9:
6:
4:
3:
2:
1359:
1348:
1345:
1344:
1342:
1325:
1322:
1320:
1317:
1316:
1315:
1314:
1310:
1308:
1307:
1303:
1298:
1297:
1294:
1288:
1285:
1283:
1280:
1278:
1275:
1273:
1270:
1268:
1265:
1263:
1260:
1259:
1257:
1253:
1243:
1240:
1236:
1233:
1232:
1231:
1228:
1224:
1221:
1220:
1219:
1216:
1212:
1209:
1207:
1204:
1202:
1199:
1197:
1194:
1192:
1189:
1188:
1187:
1184:
1183:
1181:
1179:
1178:
1173:
1167:
1166:Telluroketone
1164:
1162:
1159:
1158:
1156:
1154:
1150:
1144:
1141:
1139:
1136:
1134:
1131:
1129:
1126:
1124:
1121:
1120:
1118:
1116:
1112:
1106:
1103:
1101:
1098:
1097:
1095:
1093:
1089:
1083:
1080:
1078:
1075:
1073:
1070:
1068:
1065:
1063:
1060:
1058:
1055:
1053:
1052:Sulfonic acid
1050:
1048:
1045:
1043:
1042:Sulfinic acid
1040:
1038:
1037:Thiosulfonate
1035:
1033:
1030:
1028:
1027:Thiosulfinate
1025:
1023:
1022:Sulfenic acid
1020:
1018:
1015:
1013:
1010:
1006:
1003:
1002:
1001:
998:
996:
993:
992:
990:
988:
984:
978:
977:Phosphaallene
975:
973:
972:Phosphaalkyne
970:
968:
967:Phosphaalkene
965:
961:
958:
957:
956:
953:
951:
948:
946:
943:
941:
938:
934:
931:
930:
929:
926:
922:
919:
918:
917:
914:
913:
911:
909:
905:
899:
896:
894:
891:
889:
886:
884:
881:
879:
876:
874:
871:
869:
866:
864:
861:
859:
856:
854:
851:
849:
846:
844:
841:
839:
836:
834:
831:
829:
826:
824:
821:
819:
816:
814:
811:
809:
806:
804:
801:
797:
794:
792:
789:
788:
787:
784:
783:
781:
779:
775:
772:
752:
740:
737:
736:
735:
732:
728:
725:
723:
720:
719:
718:
715:
714:
712:
708:
702:
699:
697:
694:
690:
687:
686:
685:
682:
678:
675:
673:
670:
668:
665:
664:
663:
660:
659:
657:
655:
651:
645:
642:
640:
639:Ethylenedioxy
637:
633:
630:
628:
625:
624:
623:
620:
616:
613:
611:
608:
607:
606:
603:
599:
596:
595:
594:
591:
589:
586:
584:
581:
580:
578:
574:
571:
565:
559:
554:
549:
543:
540:
538:
535:
531:
528:
526:
523:
522:
521:
518:
514:
511:
509:
506:
504:
501:
499:
496:
494:
491:
489:
486:
485:
484:
481:
477:
474:
472:
469:
468:
467:
464:
460:
457:
455:
452:
450:
447:
445:
442:
440:
437:
435:
432:
431:
430:
427:
426:
424:
418:
414:
410:
403:
398:
396:
391:
389:
384:
383:
380:
369:
367:0-8053-4501-9
363:
358:
357:
348:
340:
334:
327:
321:
317:
307:
304:
302:
299:
297:
294:
293:
284:
283:Malononitrile
278:
273:
270:
269:Acetylacetone
264:
259:
256:
250:
245:
244:
243:
235:
233:
229:
225:
221:
217:
213:
209:
205:
201:
191:
170:
154:
151:
147:
143:
139:
115:
111:
107:
102:
100:
96:
92:
88:
84:
81:
76:
74:
70:
66:
62:
58:
47:with formula
46:
42:
38:
34:
30:
21:
1311:
1304:
1218:Vinyl halide
1175:
1105:Borinic acid
1100:Boronic acid
1077:Thioxanthate
470:
417:Hydrocarbons
355:
347:
333:
325:
320:
296:Methyl group
255:Malonic acid
241:
197:
137:
109:
105:
103:
77:
65:single bonds
55:; namely, a
40:
36:
32:
26:
1282:Thiocyanate
1277:Sulfonamide
1242:Perchlorate
1230:Acyl halide
1191:Fluoroethyl
1072:Thionoester
960:Phosphonium
945:Phosphinate
940:Phosphonous
928:Phosphonate
627:Hydroperoxy
449:Cyclopropyl
169:double bond
153:methylidene
1186:Haloalkane
1057:Thioketone
1012:Persulfide
908:Phosphorus
873:Isocyanate
863:Isonitrile
764:or oxygen
762:hydrogen,
758:not being
739:Orthoester
632:Dioxiranes
610:Enol ether
498:1-Propenyl
312:References
220:carbanions
148:, nor the
108:or simply
89:, such as
1319:inorganic
1153:Tellurium
1067:Thioester
1032:Sulfoxide
1017:Disulfide
1005:Sulfonium
955:Phosphine
933:Phosphite
916:Phosphate
848:Carbamate
823:Hydrazone
756:element,
754:Only one
727:Anhydride
466:Methylene
202:(such as
194:Reactions
110:methylene
80:bidentate
1341:Category
1300:See also
1235:Chloride
1161:Tellurol
1115:Selenium
1082:Xanthate
796:Ammonium
778:Nitrogen
760:carbon,
717:Carboxyl
684:Aldehyde
672:Acryloyl
654:carbonyl
558:hydrogen
513:Cumulene
290:See also
238:Examples
230:and the
216:enolates
208:carbonyl
95:aluminum
91:titanium
61:hydrogen
45:molecule
1324:organic
1123:Selenol
1047:Sulfone
1000:Sulfide
898:NONOate
893:Nitroso
883:Nitrite
878:Nitrate
868:Cyanate
858:Nitrile
843:Amidine
838:Imidate
808:Nitrene
803:Hydrazo
791:Enamine
722:Acetoxy
710:carboxy
677:Benzoyl
615:Epoxide
598:Methoxy
588:Alcohol
542:Carbene
476:Methine
306:Methyne
212:nitrile
190:group.
150:carbene
138:methano
73:alkanes
1223:Iodide
1143:Selone
987:Sulfur
696:Ketone
689:Ketene
667:Acetyl
622:Peroxy
593:Alkoxy
583:Acetal
564:oxygen
553:carbon
537:Alkyne
530:Benzyl
525:Phenyl
508:Allene
503:Crotyl
483:Alkene
471:Bridge
459:Pentyl
444:Propyl
434:Methyl
364:
83:ligand
57:carbon
1255:Other
1092:Boron
1062:Thial
995:Thiol
888:Nitro
853:Imide
833:Amide
818:Oxime
813:Imine
786:Amine
734:Ester
701:Ynone
605:Ether
576:R-O-R
551:Only
493:Allyl
488:Vinyl
454:Butyl
439:Ethyl
429:Alkyl
204:nitro
39:, or
1177:Halo
662:Acyl
562:and
520:Aryl
362:ISBN
93:and
31:, a
828:Azo
218:or
210:or
173:=CH
97:in
49:−CH
27:In
1343::
560:,
555:,
234:.
206:,
180:CH
157:CH
126:Cl
117:CH
101:.
75:.
35:,
401:e
394:t
387:v
370:.
341:.
185:2
175:2
171:(
162:2
131:2
122:2
53:−
51:2
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