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	{{chembox		{{chembox
			| Verifiedfields = changed
	| verifiedrevid = 415899026
			| Watchedfields = changed
	| Name = Sodium cyanoborohydride
			| verifiedrevid = 438800960
	| ImageFile = Sodium-cyanoborohydride-2D.png
			| Name = Sodium cyanoborohydride
	<!-- | ImageSize = 200px -->
	| ImageName = Sodium cyanoborohydride		| ImageFile = Sodium-cyanoborohydride-2D.png
			| ImageName = Line-bond structure of sodium cyanoborohydride
	| OtherNames = Sodium cyanotrihydridoborate
			| OtherNames = Sodium cyanotrihydridoborate
	| Section1 = {{Chembox Identifiers
			| IUPACName = Sodium cyanoboranuide
	| CASNo = 25895-60-7
	| CASNo_Ref = {{cascite}}		| Section1 = {{Chembox Identifiers
			|CASNo_Ref = {{cascite|correct|CAS}}
	| EINECS = 247-317-2
			|CASNo = 25895-60-7
	| PubChem = 24849595
			|UNII_Ref = {{fdacite|correct|FDA}}
	}}
			|UNII = C4I8C58P9T
	| Section2 = {{Chembox Properties
			|EINECS = 247-317-2
	| Formula = NaBH<sub>3</sub>CN
			|PubChem = 5003444
	| MolarMass = 62.84 g/mol
			|InChI = 1S/CH3BN.Na/c2-1-3;/h2H3;/q-1;+1
	| Appearance = white to off-white powder, ]
			|SMILES = C#N.
	| Density = 1.20 g/cm<sup>3</sup>
			}}
	| Solubility = soluble
			| Section2 = {{Chembox Properties
	| MeltingPt = 241 °C decomp.
			|Formula = {{chem2|Na}}
	}}
			|Na=1|B=1|H=3|C=1|N=1
	| Section7 = {{Chembox Hazards
			|Appearance = white powder, ]
	| ExternalMSDS =
			|Density = 1.083 g/cm (25°C)<sup>3</sup>
	| EUIndex = not listed
			|Solubility = 212 g/(100 mL) (29 °C)
	| NFPA-H = 3
			|SolubleOther = soluble in water, ], ], ], ] <br /> slightly soluble in ] <br /> insoluble in ]
	| NFPA-R = 2
	| NFPA-F = 2		|MeltingPtC = 242
			|MeltingPt_notes = decomposes
	| NFPA-O = W
	}}		}}
	| Section8 = {{Chembox Related		| Section3 = {{Chembox Structure
			| Coordination = 4 at boron atom
	| OtherAnions = ]
			| MolShape = ] at ] atom
	| OtherCations =
	| OtherCpds = ]
	}}		}}
			| Section7 = {{Chembox Hazards
			|ExternalSDS = Sigma Aldrich<ref>{{Sigma-Aldrich|sial|id=42077|name=Sodium cyanoborohydride |accessdate=2014-11-09}}</ref>
			|GHSPictograms = {{GHS02}}{{GHS05}}{{GHS06}}
			|GHSSignalWord =Danger
			|HPhrases = {{H-phrases|228|300|310|330|314|410}}
			|PPhrases = {{P-phrases|210|260|264|273|280|284}}
			|NFPA-H = 4
			|NFPA-F = 3
			|NFPA-R = 2
			|NFPA-S = <!--E NFPA code "E" is unknown, not accepted in ]. Please go to that talkpage if it is acceptable. DePiep 8 Nov 2014-->
			|MainHazards = Flammable solid, fatal if swallowed, in contact with skin or if inhaled<br />Contact with acids liberates very toxic gas<br />Contact with water liberates highly flammable gas
			|TLV-TWA = 5 mg/m3
	}}		}}
			| Section9 = {{Chembox Related
	'''Sodium cyanoborohydride''' is the ] with the formula ]]](]]). This colourless salt is widely used in ] for the reduction of ]s.
			|OtherAnions = ]
			|OtherCompounds = ]
			}}
			}}
			'''Sodium cyanoborohydride''' is a ] with the formula {{chem2|Na|auto=1}}. It is a colourless salt used in ] for ] including that of ] and ]. Sodium cyanoborohydride is a milder reductant than other conventional ].<ref name="Reitz-2002">{{cite journal |last1=Baxter |first1=Ellen W. |last2=Reitz |first2=Allen B. |date=9 January 2002 |title=Reductive Aminations of Carbonyl Compounds with Borohydride and Borane Reducing Agents |journal=Organic Reactions |pages=1–714 |doi=10.1002/0471264180.or059.01 |isbn=0-471-26418-0}}</ref>
	==Preparation and use==		== Structure ==
			Sodium cyanoborohydride is a salt. The ] sodium ion, <sup>+</sup>, interacts with the ] cyanoborohydride ion, <sup>−</sup>. The anionic component of the salt is ] at the ] atom.
	The reagent may be prepared, either by treating ] with ], or by reacting sodium borohydride with ]. Owing to the presence of the electron-withdrawing ] substituent, <sup>&minus;</sup> is far less nucleophilic than is <sup>&minus;</sup>, as found in ].<ref>Ellen W. Baxter, Allen B. Reitz Reductive Aminations of Carbonyl Compounds with Borohydride and Borane Reducing Agents in Organic Reactions, 2002, John Wiley and Sons. {{DOI|10.1002/0471264180.or059.01}}</ref>
			The ] ] substituent draws electron density away from the negatively charged boron; thus, reducing the electrophilic capabilities of the anionic component.<ref name="Reitz-2002" /> This electronic phenomenon causes sodium cyanoborohydride to have more mild reducing qualities than other reducing agents. For example, Na is less reducing than its counterpart ], containing <sup>−</sup>.<ref name="Reitz-2002" />
	Sodium cyanoborohydride is a mild reducing agent that converts ]s to ]s. It can be used to exchange the oxygen for an amine group on the carbonyl carbon of aldehydes or ketones when reacted with ammonia or a primary amine. Selectivity is achieved at mildly basic solutions (] 7-10). Owing to this selectivity, the reagent is ideal for ]s. This reduction is known sometimes as the Borch Reaction.<ref>{{Cite journal | author = Richard F. Borch and Mark D. Bernstein and H. Dupont Durst | title = Cyanohydridoborate Anion as a Selective Reducing Agent | journal = ] | pages = 2897–2904 | volume = 93 | issue = 12 | year = 1971 | doi = 10.1021/ja00741a013}}</ref> The salt is mildly water-sensitive, but tolerates aqueous conditions.<ref>{{cite journal | author = Timothy M. Beard and Nicholas J. Turner | title = Deracemisation and Stereoinversion of alpha-Amino Acids Using D-Amino Acid Oxidase and Hydride Reducing Agents | journal = ] | pages = 246–7 | issue = 3 | year = 2002}}</ref> In addition, sodium cyanoborohydride is often used in ] reactions, such as the opening of ].
			==Uses==
			Sodium cyanoborohydride is a mild reducing agent. It is generally used for the reduction of ]s. These reactions occur <pH 7 because the iminium ions are the actual substrates.<ref>{{cite book |doi=10.1002/047084289X.rs059.pub3 |chapter=Sodium Cyanoborohydride |title=Encyclopedia of Reagents for Organic Synthesis |date=2016 |last1=Hutchins |first1=Robert O. |last2=Hutchins |first2=Marygail K. |last3=Crawley |first3=Matthew L. |last4=Mercado-Marin |first4=Eduardo V. |last5=Sarpong |first5=Richmond |pages=1–14 |isbn=978-0-470-84289-8 }}</ref>
			], sometimes called the ''Borch reaction'', is the conversion of a ] into an ] through an intermediate ].<ref>{{OrgSynth|author=Richard F. Borch|year=1988|title=Reductive Amination with Sodium Cyanoborohydride: N,N-Dimethylcyclohexylamine|collvol=6|collvolpages=499|prep=CV6P0499}}</ref> The carbonyl is first treated with ammonia to promote imine formation by nucleophilic attack. The imine is then reduced to an amine by sodium cyanoborohydride. This reaction works on both aldehydes and ketones. The carbonyl can be treated with ], a ], or a secondary amine to produce, respectively, 1°, 2°, and 3° amines.<ref>{{cite journal |author=Richard F. Borch and Mark D. Bernstein and H. Dupont Durst |year=1971 |title=Cyanohydridoborate Anion as a Selective Reducing Agent |journal=] |volume=93 |issue=12 |pages=2897–2904 |doi=10.1021/ja00741a013}}</ref>
			] ] and aldehydes can be reductively ] using sodium cyanoborohydride.<ref name=":0">{{cite journal |last1=Box |first1=Vernon G. S. |last2=Meleties |first2=Panayiotis C. |date=1998-09-24 |title=Reductive, selective deoxygenation of acylbenzofurans, aromatic aldehydes and ketones with NaBH3CN-TMSCl |url=https://www.sciencedirect.com/science/article/pii/S0040403998015196 |journal=Tetrahedron Letters |volume=39 |issue=39 |pages=7059–7062 |doi=10.1016/S0040-4039(98)01519-6 |issn=0040-4039}}</ref> This means that the carbonyl oxygen is being removed completely from the molecule. Deoxygenation using sodium cyanoborohydride is often done in the presence of ], or TMSCl.<ref name=":0" />
			== Preparation ==
			Sodium cyanoborohydride can be purchased from most chemical suppliers. It can be synthesized by combining ] and ].<ref name=":1">{{cite journal |last=Hui |first=Benjamin C. |date=October 1980 |title=Synthesis and properties of borohydride derivatives |url=https://pubs.acs.org/doi/abs/10.1021/ic50212a075 |journal=Inorganic Chemistry |language=en |volume=19 |issue=10 |pages=3185–3186 |doi=10.1021/ic50212a075 |issn=0020-1669}}</ref>
			:{{chem2|BH3*thf + NaCN -> NaBH3CN + thf}}
			== Selectivity ==
			Since sodium cyanoborohydride is a mild reducing agent, it gives good ] for reaction with certain ]s in the presence of others. For example, sodium cyanoborohydride is generally incapable of reducing ]s, ]s, ]s and ]s, ]s, or ]s.<ref name=":2">{{cite journal |last=LANE |first=Clinton F. |date=1975 |title=Sodium Cyanoborohydride - A Highly Selective Reducing Agent for Organic Functional Groups |url=http://dx.doi.org/10.1055/s-1975-23685 |journal=Synthesis |volume=1975 |issue=3 |pages=135–146 |doi=10.1055/s-1975-23685 |s2cid=95157786 |issn=0039-7881}}</ref> Therefore, it can selectively reduce some functionalities in the presence of others.
			Some examples of selective reduction include:
			* Reduction of ] ions in the presence of ]s<ref name=":2" />
			* Reduction of ]s in the presence of ]s and esters.<ref>{{cite journal |last1=Paul |first1=Avishek |last2=Shipman |first2=Michael A. |last3=Onabule |first3=Dolapo Y. |last4=Sproules |first4=Stephen |last5=Symes |first5=Mark D. |date=2021-04-15 |title=Selective aldehyde reductions in neutral water catalysed by encapsulation in a supramolecular cage |journal=Chemical Science |language=en |volume=12 |issue=14 |pages=5082–5090 |doi=10.1039/D1SC00896J |issn=2041-6539 |pmc=8179549 |pmid=34163748}}</ref>
			* Reduction of aldehydes in the presence of ]s<ref name=":2" />
			The selectivity of this reducing agent makes it an important tool in ]. It allows for specific modifications to be made to complex organic molecules.
			== History ==
			] was the first to synthesize a cyanoborohydride by treating ] with ] in 1951.<ref name=":2" /> The corresponding compound, sodium cyanoborohydride, was synthesized following a similar rationale by reacting ] with ].<ref name=":3">{{cite book |url=https://pubs.acs.org/doi/book/10.1021/bk-1996-0641 |title=Reductions in Organic Synthesis: Recent Advances and Practical Applications |date=1996-08-13 |publisher=American Chemical Society |isbn=978-0-8412-3381-2 |editor-last=Abdel-Magid |editor-first=Ahmed F. |series=ACS Symposium Series |volume=641 |location=Washington, DC |language=en |doi=10.1021/bk-1996-0641.ch001}}</ref> The synthesis was later refined to use ] and ] in ] making the process safer.<ref name=":3" />
			==See also==
			* ] – a milder reductant, but unstable in water
			* ] – a stronger, cheaper reductant
	==References==		==References==
	{{reflist}}		{{reflist}}
			{{Sodium compounds}}
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	{{inorganic-compound-stub}}		{{inorganic-compound-stub}}
	{{Sodium compounds}}
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	]