喻愛(ài)和+邱仁華+許新華
摘要:在催化劑氫氧化銫存在下,DMF做溶劑,室溫、空氣氛圍中亞磷酸二乙酯與炔硒醚不是發(fā)生預(yù)期的加成反應(yīng),而是還原斷裂SeCsP鍵,得到相應(yīng)的端炔和磷酸硒酯,收率89%~95%.考察了與炔及硒相連的取代基對(duì)反應(yīng)的影響,結(jié)果表明,取代基的電性對(duì)反應(yīng)沒(méi)有明顯的影響.反應(yīng)機(jī)理為氫氧化銫與亞磷酸二乙酯反應(yīng)生成的(EtO)2P-(O)Cs+親核進(jìn)攻炔硒醚中的Se生成磷酸硒酯和RC≡C-Cs+,RC≡C-Cs+隨后水解得到RC≡CH,同時(shí)形成催化劑氫氧化銫.本方法為斷裂SeCsP提供了一條新的簡(jiǎn)便且有效的路徑.
關(guān)鍵詞:氫氧化銫;炔硒醚;亞磷酸二乙酯;磷酸硒酯;合成
中圖分類(lèi)號(hào):O621.3 文獻(xiàn)標(biāo)識(shí)碼:A
硒原子具有空的4d軌道,對(duì)碳負(fù)離子有很好的穩(wěn)定作用,芳硒基基團(tuán)在有機(jī)合成中常作為保護(hù)基團(tuán).例如,用witting反應(yīng)制備炔烴是一種重要的合成方法(Scheme 1) \[1\].然而為了形成穩(wěn)定的磷葉立德中間體, R1必須是吸電子基如酯基,氰基等.而且這種方法具有局限性,不能制備端炔.
關(guān)于炔硒醚脫保護(hù),已經(jīng)有一些文獻(xiàn)報(bào)道,如使用正丁基鋰或者間氯過(guò)氧苯甲酸脫保護(hù)\[2\];使用Cp2TiCl2/itBuMgBr體系脫保護(hù)\[3\];使用三丁基錫烷與偶氮二異丁氰使炔硒醚脫保護(hù)等\[4\].這些方法使用的正丁基鋰及格式試劑對(duì)水十分敏感,需要嚴(yán)格的無(wú)水操作;間氯過(guò)氧苯甲酸及偶氮二異丁氰是易爆的危險(xiǎn)物質(zhì).因此,發(fā)展簡(jiǎn)便的去硒化方法,對(duì)于端炔的制備具有很大意義.
炔硒醚是合成轉(zhuǎn)化的重要中間體\[5-17\].通過(guò)與親電試劑或親核試劑加成,可以得到雙官能團(tuán)烯烴.氫氧化銫是無(wú)機(jī)超強(qiáng)堿,它能與弱酸性物質(zhì)反應(yīng)形成強(qiáng)親核性的陰離子\[18-19\].P-H鍵是極性鍵,氫表現(xiàn)出一定酸性,它應(yīng)能與氫氧化銫反應(yīng)形成親核性磷負(fù)離子.因此,設(shè)想氫氧化銫催化O,O二烷基亞膦酸酯與炔硒醚進(jìn)行加成,以期制備含磷和硒的新型的雙官能團(tuán)烯烴.但是,實(shí)驗(yàn)表明,氫氧化銫催化下,亞磷酸酯并不能對(duì)炔硒醚進(jìn)行加成,而是發(fā)生炔硒醚的去硒化反應(yīng).本文報(bào)道這一研究結(jié)果.
1實(shí)驗(yàn)部分
1.1儀器與試劑
31P NMR (TMS為內(nèi)標(biāo)),1H NMR (TMS為內(nèi)標(biāo)),13C NMR(以TMS 為內(nèi)標(biāo))用 INOVA400 型儀測(cè)定,質(zhì)譜由HP5989A 測(cè)定.溶劑 DMF未經(jīng)除水處理,硅膠為青島海洋化工廠產(chǎn)品,氫氧化銫從 Aldrich 公司購(gòu)買(mǎi).
1.2實(shí)驗(yàn)方法
在室溫及氮?dú)庀?,?.0 mmol的亞磷酸二乙酯與0.2 mmol 氫氧化銫加入到5.0 mL DMF中攪拌0.5 h,然后加入1.0 mmol 炔硒醚繼續(xù)攪拌,TLC追蹤反應(yīng)進(jìn)程,待炔硒醚消耗完,停止反應(yīng),加入20 mL水,用乙酸乙酯(15 mL×3)萃取,合并有機(jī)相,有機(jī)相用水洗 (20 mL×2),無(wú)水硫酸鈉干燥.柱層析純化,先用純石油醚做洗脫機(jī)將端炔沖下來(lái),再用石油醚/乙酸乙酯(V∶V=1∶1)做洗脫機(jī)將磷酸硒酯分離出來(lái),即得產(chǎn)物2a~2f及3a~3d.
2結(jié)果與討論
以3苯氧丙炔基苯硒醚與亞磷酸二乙酯的反應(yīng)為模型 (Scheme 3).在室溫及氮?dú)庀拢瑢?.0 mmol亞磷酸二乙酯與0.2 mmol 氫氧化銫加入到5.0 mL DMF中攪拌0.5 h,然后加入1.0 mmol的3苯氧丙炔基苯基硒醚繼續(xù)攪拌,TLC追蹤反應(yīng)進(jìn)程,發(fā)現(xiàn)兩個(gè)新點(diǎn),分離并對(duì)反產(chǎn)物進(jìn)行表征,產(chǎn)物為3苯氧丙炔和O,O二乙基Se苯基磷酸酯.這一結(jié)果表明,氫氧化銫催化下,亞磷酸二乙酯并不能對(duì)炔硒醚進(jìn)行加成,而是發(fā)生炔硒醚的去硒化反應(yīng).
采用上述投料比,空氣氛圍中,室溫下,以3苯氧丙炔基苯基硒醚與亞磷酸二乙酯的反應(yīng)為模型,考察溶劑與時(shí)間對(duì)反應(yīng)的影響.結(jié)果見(jiàn)表1.
96 反應(yīng)條件: 反應(yīng)物均為1.0 mmol, CsOH 0.2 mmol, 在室溫下反應(yīng).
從表1知,用二氯甲烷、甲苯作溶劑,在室溫幾乎不反應(yīng),延長(zhǎng)反應(yīng)時(shí)間,產(chǎn)率有所提高,但不顯著.以乙醇或THF作溶劑,在室溫反應(yīng)效果比二氯甲烷、甲苯好,但不及DMF與DMSO.由于DMSO毒性大,所以用DMF作溶劑是一種較佳選擇.
氫氧化銫在DMF與DMSO中活性大,是因?yàn)镈MF與DMSO是偶極非質(zhì)子溶劑,偶極的負(fù)端對(duì)銫離子有強(qiáng)的靜電力,導(dǎo)致與之鍵合的陰離子(EtO)2P- (O)之間距離增大,使(EtO)2P(O)表現(xiàn)出強(qiáng)的親核性.
隨后以DMF做溶劑,采用上述投料比,空氣氛圍中,室溫下反應(yīng)6 h,以3苯氧丙炔基苯基硒醚與亞磷酸二乙酯為模型,考察催化劑用量對(duì)反應(yīng)的影響.結(jié)果見(jiàn)表2.
95 反應(yīng)條件:反應(yīng)物均為1.0mmol, 堿用量0.2mmol, DMF做溶劑,在室溫下反應(yīng)6 h.
由表3可知,在相同條件下,CsOH表現(xiàn)出最好的催化效果.
CsOH的堿性比表3中其他堿金屬氫氧化物強(qiáng),是因?yàn)殇C離子體積最大,與陰離子OH-之間靜電力小,使OH-表現(xiàn)出更大活性;同樣與Cs+鍵合的磷負(fù)離子 (EtO)2P-(O)也表現(xiàn)出強(qiáng)的親核性.
在上述實(shí)驗(yàn)基礎(chǔ)上,系統(tǒng)考察不同的炔硒醚與亞磷酸二乙酯的反應(yīng)(Scheme 4), 結(jié)果見(jiàn)表
89反應(yīng)條件:反應(yīng)物均為1.0mmol, CsOH用量0.2mmol, DMF做溶劑,在室溫下反應(yīng).
表4表明,以DMF作溶劑,在20 mol% CsOH存在下,不同的炔硒醚與亞磷酸二乙酯均能反應(yīng),炔硒醚中芳基電負(fù)性上取代基對(duì)收率影響不大.
氫氧化銫催化炔硒醚與亞磷酸二乙酯反應(yīng)可能機(jī)理表示如下(Scheme 5):
在上述催化循環(huán)中,氫氧化銫與亞磷酸二乙酯反應(yīng)生成的(EtO)2P-(O)Cs+親核進(jìn)攻炔硒醚中的Se生成磷酸硒酯和RC≡C-Cs+,RC≡C-Cs+隨后水解得到RC≡CH,同時(shí)形成催化劑氫氧化銫.
以無(wú)水DMF和含水量0.5%的DMF作溶劑,結(jié)果表明,在含水溶劑中,反應(yīng)速度較快.
3結(jié)論
氫氧化銫催化下,亞磷酸二乙酯并不能對(duì)炔硒醚進(jìn)行加成,而是親核進(jìn)攻炔硒醚中的硒,生成端炔和磷酸硒酯.本研究的這種意外發(fā)現(xiàn),為硒醚的脫保護(hù)提供了一條簡(jiǎn)便有效的新途徑.與文獻(xiàn)報(bào)道的炔硒醚脫保護(hù)方法相比,本方法不使用活潑、不便于操作的試劑,不需要使用易爆的過(guò)氧化物,溶劑也無(wú)需進(jìn)行除水處理,僅使用催化劑氫氧化銫,且具有反應(yīng)條件溫和,收率高等優(yōu)點(diǎn).
參考文獻(xiàn)
[1] BRAGA A L, COMASSETO J V, PETRAGNANI N. An intramolecular Wittig reaction leading to protected terminal acetylenes[J]. Synthesis, 1984, 3:240-243.
[2]COMASSETO J V, SILVEIRA C C, FERREIRA J T B, et al. The facile deselenation of acetylenic selenides[J]. Synthetic Communications, 1986, 16(3):283-290.
[3]李言杰,曾紀(jì)朝,許新華,等. Cp2TiCl2/iBuMgBr還原斷裂SeCsp鍵反應(yīng)研究[J]. 有機(jī)化學(xué), 2005, 25(10):1227-1229.
LI Yanjie, ZENG Jichao, XU Xinhua, et al. Cleavage of SeCsp bond by Cp2TiCl2/iBuMgBr[J]. Youji Huaxue, 2005, 25(10):1227-1229.(In Chinese)
[4]YOSHIMATSU M, OTANI T, MATSUDA S, et al. Scandiumcatalyzed carboncarbon bondforming reactions of 3sulfanyl and 3selanylpropargyl alcohols[J]. Organic Letters, 2008, 10(19):4251-4254.
[5]SHENG S, LIU X. Onepot synthesis of selenoesters from alkynyl aryl selenides[J]. Organic Preparations and Procedures International, 2002, 34(5):499-502.
[6]TIECCO M, TESTAFERRI L, TEMPERINI A, et al. Synthesis of substituted Sephenyl selenocarboxylates from terminal alkynes[J]. European Journal of Organic Chemistry, 2004, 16:3447-3458.
[7]PREZBALADO C, LUCACCIONI F, MARK I E. Stereoselective synthesis of (E)1iodo1selenoalkenes via hydroaluminationiodination of 1alkynyl selenides[J]. Tetrahedron Letters, 2005, 46(29):4883-4886.
[8]CAI M Z, JIANG M H, LI H G. A facile stereoselective synthesis of (E)1arylseleno2arylsulfanylethenes via hydrozirconation of arylselenoethynes[J]. Journal of Chemical Research, 2006, 11:702-704.
[9]PREZBALADO C, MARK I E. 1Iodo1selenoalkenes as versatile alkene 1,1dianion equivalents. Novel connective approach towards the tetrahydropyran subunit of polycavernoside A[J]. Tetrahedron, 2006, 62(10):2331-2349.
[10]MANARIN F, ROEHRS J A, GAY R M, et al. Electrophilic cyclization of 2chalcogenealkynylanisoles: versatile access to 2chalcogenbenzo[b]furans[J]. Journal of Organic Chemistry, 2009, 74(5):2153-2162.
[11]MANARIN F, ROEHRS J A, BRAND O R, et al. Synthesis of 3alkynyl2(methylsulfanyl)benzo[b]furans via Sonogashira crosscoupling of 3iodo2(methylsulfanyl)benzo[b]furans with terminal alkynes[J]. Synthesis, 2009, 23:4001-4009.
[12]YOSHIMATSU M, WATANABE H, KOKETSU E. New cyclization of 4oxahepta1,6diynes bearing sulfur and selenium functional groups[J]. Organic Letters, 2010, 12(18):4192-4194.
[13]LARA R G, BORGES E L, LENARDO E J. Addition of thiols to phenylselenoalkynes using KF/alumina under solventfree conditions[J]. Journal of the Brazilian Chemical Society, 2010, 21(11):2125-2129.
[14]OHTA K, OKETSU E K, AGASE Y N, et al. Lewis acidcatalyzed propargylic etherification and sulfanylation from alcohols in MeNO2H2O[J]. Chemical & Pharmaceutical Bulletin, 2011, 59(9):1133-1140.
[15]AVERSA M C, BARATTUCCI A, BONACCORSI P. Regio and stereocontrolled synthesis of (Z)α(Phenylseleno)sulfinyl and sulfonyl alkenes via sulfenic acids, and a study of their reactivity[J]. European Journal of Organic Chemistry, 2011(28):5668-5673.
[16]PERIN G, BORGES E L, ALVES D. Highly stereoselective method to prepare bisphenylchalcogen alkenes via addition of chalcogenolate to phenylseleno alkynes[J]. Tetrahedron Letters, 2012, 53(16):2066-2069.
[17]TAKAHASHI N, NAGASE Y, TANABE G, et al. Synthesis of 3methyl and 3,4dimethylfurans using alkoxide, thiolate, and phenoxidemediated cyclization of 4oxahepta1,6diynes bearing sulfur and selenium functional groups[J]. Tetrahedron, 2012, 68(5):1566-1580.
[18]夏湘,鄒康兵,許新華,等.氫氧化銫催化二硫醚、二碲醚與端炔反應(yīng)研究[J].化學(xué)學(xué)報(bào), 2008, 66(14):1749-1752.
XIA Xiang, ZOU Kangbing, XU Xinhua, et al. Study of cesium hydroxidecatalyzed reactions of diaryl disulfides and ditellurides with terminal acetylenes[J]. Acta Chimica Sinicn, 2008, 66(14):1749-1752. (In Chinese)
[19]王小勇,李治章,許新華,等.氫氧化銫催化端炔氫硒化: 高立體區(qū)域選擇性合成(E)1芳硒基烯烴[J].有機(jī)化學(xué), 2013, 33(3):558-561.
WANG Xiaoyong, LI Zhizhang, XU Xinhua, et al. Hydroselenation of terminal alkynes catalyzed by cesium hydroxide: highly stereo and regioselective synthesis of (E)1arylselenoalkenes[J]. Chinese Journal of Organic Chemistry, 2013, 33(3)558-561.(In Chinese)
[20]LI G, ZHAO G. Efficient acetylation of alcohols and phenols catalyzed by recyclable lithium bis(perfluoroalkylsulfonyl)imide[J]. Synthetic Communications, 2013, 43(1):34-43.
[21]QIU W W, SURENDRA K, YIN L, et al. Selective formation of sixmembered oxa and carbocycles by the In(III)activated ring closure of acetylenic substrates[J]. Organic Letters, 2011, 13(21):5893-5895.
[22]FENG Y S, XIE C Q, QIAO W L, et al. Palladiumcatalyzed trifluoroethylation of terminal alkynes with 1,1,1trifluoro2iodoethane[J]. Organic Letters, 2013, 15, 936-939.
[23]FUJII A, MILLER S I. Nucleophilic substitution at acetylenic carbon. Kinetics and mechanism of the Arbuzov reaction of substituted phenylbromoand phenylchloroacetylenes with triethyl phosphite[J]. Journal of the American Chemical Society, 1971, 93(15):3694-3700.
[24]LAMBERT J B, LARSON E G, BOSCH R J. Stereomutation in the Seyferth reaction[J]. Journal of the American Chemical Society, 1985, 107(19):5443-5447.
[25]NELSON D J, BLUE C D, BROWN H C. Hydroboration kinetics. 5. Kinetics of the reaction of 9borabicyclo[3.3.1]nonane with representative haloalkynes in carbon tetrachloride. The effect of halogen substitution upon the stoichiometry and rate of hydroboration[J]. Journal of the American Chemical Society, 1982, 104(18):4913-4917.
[26]XU Q, LIANG C G, HUANG X. Free radical reaction of dialkyl phosphites and organic dichalcogenides: A new facile and convenient preparation of arylselenophosphates[J]. Synthetic Communications, 2003, 33(16):2777-2785.
[27]GAO Y X, TANG G, ZHAO Y F. A novel and general method for the formation of Saryl, Searyl, and Tearyl phosphorochalcogenoates[J]. Synthesis, 2009, 7:1081-1086.
[13]LARA R G, BORGES E L, LENARDO E J. Addition of thiols to phenylselenoalkynes using KF/alumina under solventfree conditions[J]. Journal of the Brazilian Chemical Society, 2010, 21(11):2125-2129.
[14]OHTA K, OKETSU E K, AGASE Y N, et al. Lewis acidcatalyzed propargylic etherification and sulfanylation from alcohols in MeNO2H2O[J]. Chemical & Pharmaceutical Bulletin, 2011, 59(9):1133-1140.
[15]AVERSA M C, BARATTUCCI A, BONACCORSI P. Regio and stereocontrolled synthesis of (Z)α(Phenylseleno)sulfinyl and sulfonyl alkenes via sulfenic acids, and a study of their reactivity[J]. European Journal of Organic Chemistry, 2011(28):5668-5673.
[16]PERIN G, BORGES E L, ALVES D. Highly stereoselective method to prepare bisphenylchalcogen alkenes via addition of chalcogenolate to phenylseleno alkynes[J]. Tetrahedron Letters, 2012, 53(16):2066-2069.
[17]TAKAHASHI N, NAGASE Y, TANABE G, et al. Synthesis of 3methyl and 3,4dimethylfurans using alkoxide, thiolate, and phenoxidemediated cyclization of 4oxahepta1,6diynes bearing sulfur and selenium functional groups[J]. Tetrahedron, 2012, 68(5):1566-1580.
[18]夏湘,鄒康兵,許新華,等.氫氧化銫催化二硫醚、二碲醚與端炔反應(yīng)研究[J].化學(xué)學(xué)報(bào), 2008, 66(14):1749-1752.
XIA Xiang, ZOU Kangbing, XU Xinhua, et al. Study of cesium hydroxidecatalyzed reactions of diaryl disulfides and ditellurides with terminal acetylenes[J]. Acta Chimica Sinicn, 2008, 66(14):1749-1752. (In Chinese)
[19]王小勇,李治章,許新華,等.氫氧化銫催化端炔氫硒化: 高立體區(qū)域選擇性合成(E)1芳硒基烯烴[J].有機(jī)化學(xué), 2013, 33(3):558-561.
WANG Xiaoyong, LI Zhizhang, XU Xinhua, et al. Hydroselenation of terminal alkynes catalyzed by cesium hydroxide: highly stereo and regioselective synthesis of (E)1arylselenoalkenes[J]. Chinese Journal of Organic Chemistry, 2013, 33(3)558-561.(In Chinese)
[20]LI G, ZHAO G. Efficient acetylation of alcohols and phenols catalyzed by recyclable lithium bis(perfluoroalkylsulfonyl)imide[J]. Synthetic Communications, 2013, 43(1):34-43.
[21]QIU W W, SURENDRA K, YIN L, et al. Selective formation of sixmembered oxa and carbocycles by the In(III)activated ring closure of acetylenic substrates[J]. Organic Letters, 2011, 13(21):5893-5895.
[22]FENG Y S, XIE C Q, QIAO W L, et al. Palladiumcatalyzed trifluoroethylation of terminal alkynes with 1,1,1trifluoro2iodoethane[J]. Organic Letters, 2013, 15, 936-939.
[23]FUJII A, MILLER S I. Nucleophilic substitution at acetylenic carbon. Kinetics and mechanism of the Arbuzov reaction of substituted phenylbromoand phenylchloroacetylenes with triethyl phosphite[J]. Journal of the American Chemical Society, 1971, 93(15):3694-3700.
[24]LAMBERT J B, LARSON E G, BOSCH R J. Stereomutation in the Seyferth reaction[J]. Journal of the American Chemical Society, 1985, 107(19):5443-5447.
[25]NELSON D J, BLUE C D, BROWN H C. Hydroboration kinetics. 5. Kinetics of the reaction of 9borabicyclo[3.3.1]nonane with representative haloalkynes in carbon tetrachloride. The effect of halogen substitution upon the stoichiometry and rate of hydroboration[J]. Journal of the American Chemical Society, 1982, 104(18):4913-4917.
[26]XU Q, LIANG C G, HUANG X. Free radical reaction of dialkyl phosphites and organic dichalcogenides: A new facile and convenient preparation of arylselenophosphates[J]. Synthetic Communications, 2003, 33(16):2777-2785.
[27]GAO Y X, TANG G, ZHAO Y F. A novel and general method for the formation of Saryl, Searyl, and Tearyl phosphorochalcogenoates[J]. Synthesis, 2009, 7:1081-1086.
[13]LARA R G, BORGES E L, LENARDO E J. Addition of thiols to phenylselenoalkynes using KF/alumina under solventfree conditions[J]. Journal of the Brazilian Chemical Society, 2010, 21(11):2125-2129.
[14]OHTA K, OKETSU E K, AGASE Y N, et al. Lewis acidcatalyzed propargylic etherification and sulfanylation from alcohols in MeNO2H2O[J]. Chemical & Pharmaceutical Bulletin, 2011, 59(9):1133-1140.
[15]AVERSA M C, BARATTUCCI A, BONACCORSI P. Regio and stereocontrolled synthesis of (Z)α(Phenylseleno)sulfinyl and sulfonyl alkenes via sulfenic acids, and a study of their reactivity[J]. European Journal of Organic Chemistry, 2011(28):5668-5673.
[16]PERIN G, BORGES E L, ALVES D. Highly stereoselective method to prepare bisphenylchalcogen alkenes via addition of chalcogenolate to phenylseleno alkynes[J]. Tetrahedron Letters, 2012, 53(16):2066-2069.
[17]TAKAHASHI N, NAGASE Y, TANABE G, et al. Synthesis of 3methyl and 3,4dimethylfurans using alkoxide, thiolate, and phenoxidemediated cyclization of 4oxahepta1,6diynes bearing sulfur and selenium functional groups[J]. Tetrahedron, 2012, 68(5):1566-1580.
[18]夏湘,鄒康兵,許新華,等.氫氧化銫催化二硫醚、二碲醚與端炔反應(yīng)研究[J].化學(xué)學(xué)報(bào), 2008, 66(14):1749-1752.
XIA Xiang, ZOU Kangbing, XU Xinhua, et al. Study of cesium hydroxidecatalyzed reactions of diaryl disulfides and ditellurides with terminal acetylenes[J]. Acta Chimica Sinicn, 2008, 66(14):1749-1752. (In Chinese)
[19]王小勇,李治章,許新華,等.氫氧化銫催化端炔氫硒化: 高立體區(qū)域選擇性合成(E)1芳硒基烯烴[J].有機(jī)化學(xué), 2013, 33(3):558-561.
WANG Xiaoyong, LI Zhizhang, XU Xinhua, et al. Hydroselenation of terminal alkynes catalyzed by cesium hydroxide: highly stereo and regioselective synthesis of (E)1arylselenoalkenes[J]. Chinese Journal of Organic Chemistry, 2013, 33(3)558-561.(In Chinese)
[20]LI G, ZHAO G. Efficient acetylation of alcohols and phenols catalyzed by recyclable lithium bis(perfluoroalkylsulfonyl)imide[J]. Synthetic Communications, 2013, 43(1):34-43.
[21]QIU W W, SURENDRA K, YIN L, et al. Selective formation of sixmembered oxa and carbocycles by the In(III)activated ring closure of acetylenic substrates[J]. Organic Letters, 2011, 13(21):5893-5895.
[22]FENG Y S, XIE C Q, QIAO W L, et al. Palladiumcatalyzed trifluoroethylation of terminal alkynes with 1,1,1trifluoro2iodoethane[J]. Organic Letters, 2013, 15, 936-939.
[23]FUJII A, MILLER S I. Nucleophilic substitution at acetylenic carbon. Kinetics and mechanism of the Arbuzov reaction of substituted phenylbromoand phenylchloroacetylenes with triethyl phosphite[J]. Journal of the American Chemical Society, 1971, 93(15):3694-3700.
[24]LAMBERT J B, LARSON E G, BOSCH R J. Stereomutation in the Seyferth reaction[J]. Journal of the American Chemical Society, 1985, 107(19):5443-5447.
[25]NELSON D J, BLUE C D, BROWN H C. Hydroboration kinetics. 5. Kinetics of the reaction of 9borabicyclo[3.3.1]nonane with representative haloalkynes in carbon tetrachloride. The effect of halogen substitution upon the stoichiometry and rate of hydroboration[J]. Journal of the American Chemical Society, 1982, 104(18):4913-4917.
[26]XU Q, LIANG C G, HUANG X. Free radical reaction of dialkyl phosphites and organic dichalcogenides: A new facile and convenient preparation of arylselenophosphates[J]. Synthetic Communications, 2003, 33(16):2777-2785.
[27]GAO Y X, TANG G, ZHAO Y F. A novel and general method for the formation of Saryl, Searyl, and Tearyl phosphorochalcogenoates[J]. Synthesis, 2009, 7:1081-1086.