Organotellurium chemistry

Organotellurium chemistry in chemistry describes the synthesis and properties of chemical compounds containing a carbon to tellurium chemical bond.^[1] Organotellurium chemistry was developed in the wake of organoselenium chemistry and, sharing the same group in the periodic table, both chemistries have much in common.

Functional groups

General structures of some organotellurium compounds

The Te analogues of common organosulfur functional groups are known. Tellurols are unstable. Diorganomono- and ditellurides are the most commonly encountered organotellurium compounds. Telluroxides (R₂TeO) are also known.

Synthesis

Commonly used tellurium based reagents are hydrogen telluride, NaHTe, sodium telluride, and PhTeLi. Because Te is insoluble and polymeric, it is often not a useful precursor to organotellurium compounds, but it is attacked by hydride reducing agents:

Te + 2LiBHEt₃ → Li₂Te + H₂ + 2 BEt3

and organolithium compounds:

Te + RLi → RTeLi

One departure from S and Se chemistry, is the availability of the tetrachloride TeCl4.^[2] Tellurium tetrachloride reacts with alkenes and alkynes to the chloro tellurium trichloride addition product:

RCH=CH₂ + TeCl₄ → RCH(Cl)-CH₂TeCl₃

These organotellurium derivatives are susceptible to further reactions.

Applications

Organotellurium compounds have few applications. Dimethyl telluride is used to in the metalorganic vapour phase epitaxy where it serves as a volatile source of Te. It is the only organotellurium compound that has been quantified in environmental samples.^[3]

Organic synthesis

Diphenyl ditelluride is used as a source of PhTe⁻ in organic synthesis. Some of its reactions are:

Organic reduction of aldehydes, alkenes, alkynes, nitro compounds, oxiranes to alkenes
Debromination of vicinal dibromides with E2 elimination

Other methods in organotellurium chemistry include:

Tellurium in vinylic tellurium trichlorides can be replaced by halides with a variety of reagents (iodine, NBS)
Detellurative cross-coupling reaction: Compounds of the type Ar₂TeCl₂ engage in a coupling reaction to the corresponding biaryls with Raney nickel or palladium^[4]

Another type is this Stille reaction:^[5]

Hydrotelluration: Compounds of the type RTeH react with alkynes R'CCH to R'HCCTeR with anti addition to a Z-alkene. In contrast hydrostannylation, hydrozirconation and hydroalumination in similar reactions react with syn addition.
Te/Li exchange in transmetallation^[6] is used in the synthesis of lithium reagents with demanding functional groups.
Allylic oxidation: like the selenium counterpart selenoxide oxidation, allylic telluroxides undergo [2,3]-sigmatropic rearrangements forming allylic alcohols after hydrolysis.
Olefin synthesis: Like the selenium counterpart selenoxide elimination, certain telluroxides (RTeOR) can form alkenes on heating.

CH				He
CLi	CBe	CB	CC	CN	CO	CF	Ne
CNa	CMg	CAl	CSi	CP	CS	CCl	CAr
CK	CCa	CSc	CTi	CV	CCr	CMn	CFe	CCo	CNi	CCu	CZn	CGa	CGe	CAs	CSe	CBr	CKr
CRb	CSr	CY	CZr	CNb	CMo	CTc	CRu	CRh	CPd	CAg	CCd	CIn	CSn	CSb	CTe	CI	CXe
CCs	CBa		CHf	CTa	CW	CRe	COs	CIr	CPt	CAu	CHg	CTl	CPb	CBi	CPo	CAt	Rn
Fr	CRa	Rf	Db	CSg	Bh	Hs	Mt	Ds	Rg	Cn	Nh	Fl	Mc	Lv	Ts	Og
	↓
	CLa	CCe	CPr	CNd	CPm	CSm	CEu	CGd	CTb	CDy	CHo	CEr	CTm	CYb	CLu
	Ac	CTh	CPa	CU	CNp	CPu	CAm	CCm	CBk	CCf	CEs	Fm	Md	No	Lr

**Chemical bonds to carbon**
Core organic chemistry	Many uses in chemistry
Academic research, but no widespread use	Bond unknown

References

↑ Nicola Petragnani, Tellurium in Organic Synthesiss 1994, Academic Press, New York. ISBN 0-12-552810-8
↑ Lars Engman, "Tellurium(IV) Chloride" E-EROS. 2001. doi:10.1002/047084289X.rt003
↑ Wallschläger, D.; Feldmann, F. (2010). Formation, Occurrence, Significance, and Analysis of Organoselenium and Organotellurium Compounds in the Environment. Metal Ions in Life Sciences. 7, Organometallics in Environment and Toxicology. RSC Publishing. pp. 319–364. ISBN 978-1-84755-177-1.
↑ For an example see: Organic Syntheses, Coll. Vol. 6, p.468 (1988); Vol. 57, p.18 (1977). http://orgsynth.org/orgsyn/pdfs/CV6P0468.pdf
↑ Palladium- and copper-catalyzed cross-coupling and carbonylative cross-coupling of organotellurium compounds with organostannanes (Chem. Commun. 1999, 2117) - Royal Society of Chemistry Suk-Ku Kang, Sang-Woo Lee and Hyung-Chul Ryu Link
↑ For an example see: Organic Syntheses, Coll. Vol. 9, p.234 (1998); Vol. 72, p.154 (1995). http://orgsynth.org/orgsyn/pdfs/CV9P0234.pdf

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CH																	He
CLi	CBe											CB	CC	CN	CO	CF	Ne
CNa	CMg											CAl	CSi	CP	CS	CCl	CAr
CK	CCa	CSc	CTi	CV	CCr	CMn	CFe	CCo	CNi	CCu	CZn	CGa	CGe	CAs	CSe	CBr	CKr
CRb	CSr	CY	CZr	CNb	CMo	CTc	CRu	CRh	CPd	CAg	CCd	CIn	CSn	CSb	CTe	CI	CXe
CCs	CBa		CHf	CTa	CW	CRe	COs	CIr	CPt	CAu	CHg	CTl	CPb	CBi	CPo	CAt	Rn
Fr	CRa		Rf	Db	CSg	Bh	Hs	Mt	Ds	Rg	Cn	Nh	Fl	Mc	Lv	Ts	Og
		↓
		CLa	CCe	CPr	CNd	CPm	CSm	CEu	CGd	CTb	CDy	CHo	CEr	CTm	CYb	CLu
		Ac	CTh	CPa	CU	CNp	CPu	CAm	CCm	CBk	CCf	CEs	Fm	Md	No	Lr

CH																	He
CLi	CBe											CB	CC	CN	CO	CF	Ne
CNa	CMg											CAl	CSi	CP	CS	CCl	CAr
CK	CCa	CSc	CTi	CV	CCr	CMn	CFe	CCo	CNi	CCu	CZn	CGa	CGe	CAs	CSe	CBr	CKr
CRb	CSr	CY	CZr	CNb	CMo	CTc	CRu	CRh	CPd	CAg	CCd	CIn	CSn	CSb	CTe	CI	CXe
CCs	CBa		CHf	CTa	CW	CRe	COs	CIr	CPt	CAu	CHg	CTl	CPb	CBi	CPo	CAt	Rn
Fr	CRa		Rf	Db	CSg	Bh	Hs	Mt	Ds	Rg	Cn	Nh	Fl	Mc	Lv	Ts	Og
		↓
		CLa	CCe	CPr	CNd	CPm	CSm	CEu	CGd	CTb	CDy	CHo	CEr	CTm	CYb	CLu
		Ac	CTh	CPa	CU	CNp	CPu	CAm	CCm	CBk	CCf	CEs	Fm	Md	No	Lr