111011-80-4Relevant articles and documents
Palladium-catalyzed coupling of allenylphosphonates, phenylallenes, and allenyl esters: Remarkable salt effect and routes to novel benzofurans and isocoumarins
Chakravarty, Manab,Swamy, K. C. Kumara
, p. 9128 - 9138 (2006)
(Chemical Equation Presented) Coupling reactions of allenylphosphonates (OCH2CMe2CH2O)P(O)CH=C=CRR′ [R, R′ = H (1a), R = H, R′ = Me (1b), R = R′ = Me (1c)] with aryl iodides, iodophenol, and iodobenzoic acid in the presence of palladium(II) acetate are investigated and compared with those of phenylallenes PhCH=C=CR2 [R = H (2a), Me (2b)] and allenyl esters EtO2CCH=C=CR2 [R = H (2c), Me (2d)]. While 1b and 1c couple with different stereochemical outcomes using PhI in the presence of Pd(OAc)2/PPh3/K 2CO3 to give phenyl-substituted 1,3-butadienes, 1a does not undergo coupling but isomerizes to the acetylene (OCH2CMe 2CH2O)P(O)C≡CMe (7). In the reaction of 1c with PhI, use of K2CO3 affords the butadiene (Z)-(OCH 2CMe2CH2O)P(O)CH=C(Ph)-C(Me)=CH2 (12); in contrast, the use of Ag2CO3 leads to the allene (OCH2CMe2CH2O)P(O)C(Ph)=C=CMe2 (20), showing that these bases differ very significantly in their roles. The reaction of 1a with PhI or PhB(OH)2 in the presence of Pd(OAc) 2/CsF/DMF leads mainly to (E)-(OCH2CMe2CH 2O)P(O)CH=C(Me)Ph (21) and (OCH2CMe2CH 2O)P(O)CH2-C(Ph)=CH2 (22) and is thus a net 1,2-addition of Ph-H. Compound 1b reacts with iodophenol in the presence of Pd(OAc)2/PPh3/K2CO3 to give a benzofuran that has a structure different from that obtained by using 1c under similar conditions. Treatment of 1a with iodophenol/Pd(OAc)2/CsF/DMF also gives a benzofuran whose structure is different from that obtained by using 2a under similar conditions. In the reaction with 2-iodobenzoic acid, 1a and 2c afford one type of isocoumarin, while 1b,c and 2a,b give a second type of isocoumarin. The structures of key compounds are established by X-ray crystallography. Utility of the phosphonate products in the Horner-Wadsworth- Emmons reaction is demonstrated.
New reactions of allenes, alkynes, ynamides, enynones and isothiocyanates
Swamy, K C Kumara,Gangadhararao,Anitha, Mandala,Sivakumari, A Leela,Reddy, Alla Siva,Kalyani, Adula,Allu, Srinivasarao
, (2018/07/25)
Abstract: This perspective article is related to transformations (both catalytic and non-catalytic) involving allenes, alkynes/enynones/ynamides and isothiocyanates. Part of the work from the author’s group has been reviewed along with some new reactions of (i) allenylphosphonate/allenylphosphine oxide and (ii) a P(III) isothiocyanate. Thus, the allenylphosphine oxide Ph 2P(O)C(Ph)=C=CH 2 undergoes base (DBU) catalyzed addition to the β-ketophosphonate (OCH 2CMe 2CH 2O)P(O)CH 2C(O)CH 3 at 90°C to afford the addition product Ph 2P(O)C(Ph)=C(Me)CH[C(O)Me][P(O)(OCH 2CMe 2CH 2O)]. In an analogous reaction, with DBU as the base at 140°C, isomeric vinylphosphine oxides (Z)-Ph 2P(O)C(Ph)=C(Me)CH 2[C(O)Me] and (E)-Ph 2P(O)C(Ph)=C(Me)CH 2[C(O)Me] were isolated. The E-isomer has been characterized by single crystal X-ray structure determination. In another set of studies, the reaction of P(III) isothiocyanate (OCH 2CMe 2CH 2O)P(NCS) with N-(2-bromomethyl)sulfonamide afforded an unusual product with the formula (OCH 2CMe 2CH 2O)P(O)SCH 2CH 2NHS(O) 2-(C 6H 4-4-Me) as shown by X-ray structure determination. This result is different from that obtained in the recently reported analogous reaction using phenyl isothiocyanate. Graphical Abstract: Synopsis. Base-catalyzed the addition of β-ketophosphonate or ethyl acetoacetate to allenylphosphine oxide affords vinylphosphine oxides; in the latter case, elimination of the ester group also takes place. It is also shown that reactivity of a P(III) isothiocyanate is different from that of organic isothiocyanates. [Figure not available: see fulltext.].
Synthesis of 1,4-dihydropyridine-5-phosphonates and their calcium-antagonistic and antihypertensive activities
Sakoda,Kamikawaji,Seto
, p. 2362 - 2369 (2007/10/02)
The effect of the 3-carboxylic-ester variation in 2,2-dimethyltrimethylene 3-alkoxycarbonyl-4-aryl-1,4-dihydro-2,6-dimethyl-5-pyridinephosphonate s (1) was investigated with relation to the calcium-antagonistic and antihypertensive activities: the analogs containing the alkyl groups of not more than 12 carbons and an amino functionality in the carboxylic-ester moiety were synthesized to be examined for biological activities. Among them, 2-[benzyl(phenyl)amino]-ethyl 5-(5,5-dimethyl-2-oxo-1,3,2-dioxaphosphorinan-2-yl)-1,4-dihydro-2,6-di methyl-4-(3-nitrophenyl)-3-pyridine-carboxylate hydrochloride ethanol (NZ-105) showed particularly beneficial activities and was selected for further pharmacological studies and clinical development. Some aspects of the structure-activity relationships and solid-state structure of NZ-105 by X-ray crystallographic analysis were described.
